Journal articles on the topic 'Analyse des signaux HD-sEMG'
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1
ALI, MD ASRAF, KENNETH SUNDARAJ, R. BADLISHAH AHMAD, NIZAM UDDIN AHAMED, MD ANAMUL ISLAM, and SEBASTIAN SUNDARAJ. "sEMG ACTIVITIES OF THE THREE HEADS OF THE TRICEPS BRACHII MUSCLE DURING CRICKET BOWLING." Journal of Mechanics in Medicine and Biology 16, no. 05 (August 2016): 1650075. http://dx.doi.org/10.1142/s0219519416500755.
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The aim of the present study was to analyze the surface electromyography (sEMG) activities generated by the three heads of the triceps brachii (TB) muscle among the different phases during fast and spin bowling. sEMG signals from the lateral, long and medial heads of the TB from 20 bowlers were measured individually during bowling. To analyze the sEMG activities, the root mean square (RMS) value in each bowling phase for every trial per bowler was calculated from the sEMG signals from the three heads of the TB. Higher sEMG activities at the three heads of the TB were found during the fifth phase followed by the sixth, seventh, third, fourth, second and first phases in both types of bowling. sEMG activities were significantly different among the three heads of the TB and among the seven bowling phases for both bowling types at an alpha level of [Formula: see text]. These findings will be of particular importance for assessing different physical therapies for the three headed TB muscle which can improve the performance in ball delivery of cricket bowlers.
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Herrera, Efrén V., Edgar M. Vela, Victor A. Arce, Katherine G. Molina, Nathaly S. Sánchez, Paúl J. Daza, Luis E. Herrera, and Douglas A. Plaza. "Temperature Influences at the Myoelectric Level in the Upper Extremities of the Human Body." Open Biomedical Engineering Journal 14, no. 1 (October 23, 2020): 28–42. http://dx.doi.org/10.2174/1874120702014010028.
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Objective: Nowadays, surface electromyography (sEMG) signals are used for a variety of medical interaction applications along with hardware and software interfaces. These signals require advanced techniques with different approaches that enable processing the sEMG signals acquired in the upper limb muscles of a person. Methods: The purpose of this article is to analyze the sEMG signals of the upper limb of a person exposed to temperature changes to envisage its behavior and its nature. The anticipated diagnostic is a key factor in the health field. Therefore, it is very important to develop more precise methods and techniques. For the present study, a heat chamber that allows controlling the temperature of the area where the patient rests his or her hand was designed and implemented. With the appropriate hardware interfaces, the sEMG signals of the hand were registered with MatLab/Simulink software for further analysis. The article explains the analysis and develops knowledge, through a probabilistic approach regarding the change in the sEMG signals. Results: The results show that there is an activity in the sEMG signal response due to changes in temperature and it is feasible to detect them using the proposed method. Conclusion: This finding contributes to research that seeks to characterize temperature’s effect in the biomedical field.
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Dorgham, Osama, Ibrahim Al-Mherat, Jawdat Al-Shaer, Sulieman Bani-Ahmad, and Stephen Laycock. "Smart System for Prediction of Accurate Surface Electromyography Signals Using an Artificial Neural Network." Future Internet 11, no. 1 (January 21, 2019): 25. http://dx.doi.org/10.3390/fi11010025.
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Bioelectric signals are used to measure electrical potential, but there are different types of signals. The electromyography (EMG) is a type of bioelectric signal used to monitor and recode the electrical activity of the muscles. The current work aims to model and reproduce surface EMG (SEMG) signals using an artificial neural network. Such research can aid studies into life enhancement for those suffering from damage or disease affecting their nervous system. The SEMG signal is collected from the surface above the bicep muscle through dynamic (concentric and eccentric) contraction with various loads. In this paper, we use time domain features to analyze the relationship between the amplitude of SEMG signals and the load. We extract some features (e.g., mean absolute value, root mean square, variance and standard deviation) from the collected SEMG signals to estimate the bicep’ muscle force for the various loads. Further, we use the R-squared value to depict the correlation between the SEMG amplitude and the muscle loads by linear fitting. The best performance the ANN model with 60 hidden neurons for three loads used (3 kg, 5 kg and 7 kg) has given a mean square error of 1.145, 1.3659 and 1.4238, respectively. The R-squared observed are 0.9993, 0.99999 and 0.99999 for predicting (reproduction step) of smooth SEMG signals.
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KARTHICK, P. A., G. VENUGOPAL, and S. RAMAKRISHNAN. "ANALYSIS OF SURFACE EMG SIGNALS UNDER FATIGUE AND NON-FATIGUE CONDITIONS USING B-DISTRIBUTION BASED QUADRATIC TIME FREQUENCY DISTRIBUTION." Journal of Mechanics in Medicine and Biology 15, no. 02 (April 2015): 1540028. http://dx.doi.org/10.1142/s021951941540028x.
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In this paper, an attempt has been made to analyze surface electromyography (sEMG) signals under non-fatigue and fatigue conditions using time-frequency based features. The sEMG signals are recorded from biceps brachii muscle of 50 healthy volunteers under well-defined protocol. The pre-processed signals are divided into six equal epochs. The first and last segments are considered as non-fatigue and fatigue zones respectively. Further, these signals are subjected to B-distribution based quadratic time-frequency distribution (TFD). Time frequency based features such as instantaneous median frequency (IMDF) and instantaneous mean frequency (IMNF) are extracted. The expression of spectral entropy is modified to obtain instantaneous spectral entropy (ISPEn) from the time-frequency spectrum. The results show that all the extracted features are distinct in both conditions. It is also observed that the values of all features are higher in non-fatigue zone compared to fatigue condition. It appears that this method is useful in analysing various neuromuscular conditions using sEMG signals.
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Hari, Lakshmi M., Gopinath Venugopal, and Swaminathan Ramakrishnan. "Dynamic contraction and fatigue analysis in biceps brachii muscles using synchrosqueezed wavelet transform and singular value features." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 236, no. 2 (October 11, 2021): 208–17. http://dx.doi.org/10.1177/09544119211048011.
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In this study, the dynamic contractions and the associated fatigue condition in biceps brachii muscle are analysed using Synchrosqueezed Wavelet Transform (SST) and singular value features of surface Electromyography (sEMG) signals. For this, the recorded signals are decomposed into time-frequency matrix using SST. Two analytic functions namely Morlet and Bump wavelets are utilised for the analysis. Singular Value Decomposition method is applied to this time-frequency matrix to derive the features such as Maximum Singular Value (MSV), Singular Value Entropy (SVEn) and Singular Value Energy (SVEr). The results show that both these wavelets are able to characterise nonstationary variations in sEMG signals during dynamic fatiguing contractions. Increase in values of MSV and SVEr with the progression of fatigue denotes the presence of nonstationarity in the sEMG signals. The lower values of SVEn with the progression of fatigue indicate the randomness in the signal. Thus, it appears that the proposed approach could be used to characterise dynamic muscle contractions under varied neuromuscular conditions.
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Pietraszewski, Przemysław, Artur Gołaś, Michał Krzysztofik, Marta Śrutwa, and Adam Zając. "Evaluation of Lower Limb Muscle Electromyographic Activity during 400 m Indoor Sprinting among Elite Female Athletes: A Cross-Sectional Study." International Journal of Environmental Research and Public Health 18, no. 24 (December 14, 2021): 13177. http://dx.doi.org/10.3390/ijerph182413177.
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The purpose of this cross-sectional study was to analyze changes in normalized surface electromyography (sEMG) signals for the gastrocnemius medialis, biceps femoris, gluteus maximus, tibialis anterior, and vastus lateralis muscles occurring during a 400 m indoor sprint between subsequent curved sections of the track. Ten well-trained female sprinters (age: 21 ± 4 years; body mass: 47 ± 5 kg; body height: 161 ± 7 cm; 400 m personal best: 52.4 ± 1.1 s) performed an all-out 400 m indoor sprint. Normalized sEMG signals were recorded bilaterally from the selected lower limb muscles. The two-way ANOVA (curve × side) revealed no statistically significant interaction. However, the main effect analysis showed that normalized sEMG signals significantly increased in subsequent curves run for all the studied muscles: gastrocnemius medialis (p = 0.003), biceps femoris (p < 0.0001), gluteus maximus (p = 0.044), tibialis anterior (p = 0.001), and vastus lateralis (p = 0.023), but differences between limbs were significant only for the gastrocnemius medialis (p = 0.012). The results suggest that the normalized sEMG signals for the lower limb muscles increased in successive curves during the 400 m indoor sprint. Moreover, the gastrocnemius medialis of the inner leg is highly activated while running curves; therefore, it should be properly prepared for high demands, and attention should be paid to the possibility of the occurrence of a negative adaptation, such as asymmetries.
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Wu, Na, Hao JIN, Xiachuan Pei, Shurong Dong, Jikui Luo, Ruijian Yan, and Gang Feng. "Gesture recognition system based on CNN-IndRNN and OpenBCI." MATEC Web of Conferences 336 (2021): 06003. http://dx.doi.org/10.1051/matecconf/202133606003.
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Surface electromyography (sEMG), as a key technology of non-invasive muscle computer interface, is an important method of human-computer interaction. We proposed a CNN-IndRNN (Convolutional Neural Network-Independent Recurrent Neural Network) hybrid algorithm to analyse sEMG signals and classify hand gestures. Ninapro’s dataset of 10 volunteers was used to develop the model, and by using only one time-domain feature (root mean square of sEMG), an average accuracy of 87.43% on 18 gestures is achieved. The proposed algorithm obtains a state-of-the-art classification performance with a significantly reduced model. In order to verify the robustness of the CNN-IndRNN model, a compact real¬time recognition system was constructed. The system was based on open-source hardware (OpenBCI) and a custom Python-based software. Results show that the 10-subject rock-paper-scissors gesture recognition accuracy reaches 99.1%.
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Zhu, Jianfei, Chunzhi Yi, Baichun Wei, Chifu Yang, Zhen Ding, and Feng Jiang. "The Muscle Fatigue’s Effects on the sEMG-Based Gait Phase Classification: An Experimental Study and a Novel Training Strategy." Applied Sciences 11, no. 9 (April 23, 2021): 3821. http://dx.doi.org/10.3390/app11093821.
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Surface Electromyography (sEMG) enables an intuitive control of wearable robots. The muscle fatigue-induced changes of sEMG signals might limit the long-term usage of the sEMG-based control algorithms. This paper presents the performance deterioration of sEMG-based gait phase classifiers, explains the deterioration by analyzing the time-varying changes of the extracted features, and proposes a training strategy that can improve the classifiers’ robustness against muscle fatigue. In particular, we first select some features that are commonly used in fatigue-related studies and use them to classify gait phases under muscle fatigue. Then, we analyze the time-varying characteristics of extracted features, with the aim of explaining the performance of the classifiers. Finally, we propose a training strategy that effectively improves the robustness against muscle fatigue, which contributes to an easy-to-use method. Ten subjects performing prolonged walking are recruited. Our study contributes to a novel perspective of designing gait phase classifiers under muscle fatigue.
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Feng, Fabo, R. Paul Butler, Steven S. Vogt, Matthew S. Clement, C. G. Tinney, Kaiming Cui, Masataka Aizawa, et al. "3D Selection of 167 Substellar Companions to Nearby Stars." Astrophysical Journal Supplement Series 262, no. 1 (August 26, 2022): 21. http://dx.doi.org/10.3847/1538-4365/ac7e57.
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Abstract We analyze 5108 AFGKM stars with at least five high-precision radial velocity points, as well as Gaia and Hipparcos astrometric data, utilizing a novel pipeline developed in previous work. We find 914 radial velocity signals with periods longer than 1000 days. Around these signals, 167 cold giants and 68 other types of companions are identified, through combined analyses of radial velocity, astrometry, and imaging data. Without correcting for detection bias, we estimate the minimum occurrence rate of the wide-orbit brown dwarfs to be 1.3%, and find a significant brown-dwarf valley around 40 M Jup. We also find a power-law distribution in the host binary fraction beyond 3 au, similar to that found for single stars, indicating no preference of multiplicity for brown dwarfs. Our work also reveals nine substellar systems (GJ 234 B, GJ 494 B, HD 13724 b, HD 182488 b, HD 39060 b and c, HD 4113 C, HD 42581 d, HD 7449 B, and HD 984 b) that have previously been directly imaged, and many others that are observable at existing facilities. Depending on their ages, we estimate that an additional 10–57 substellar objects within our sample can be detected with current imaging facilities, extending the imaged cold (or old) giants by an order of magnitude.
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Anders, Christoph, Klaus Sander, Frank Layher, Steffen Patenge, and Raimund W. Kinne. "Temporal and spatial relationship between gluteal muscle Surface EMG activity and the vertical component of the ground reaction force during walking." PLOS ONE 16, no. 5 (May 26, 2021): e0251758. http://dx.doi.org/10.1371/journal.pone.0251758.
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Background Optimized temporal and spatial activation of the gluteal intermuscular functional unit is essential for steady gait and minimized joint loading. Research question To analyze the temporal relationship between spatially resolved surface EMG (SEMG) of the gluteal region and the corresponding ground reaction force (GRF). Methods Healthy adults (29♀; 25♂; age 62.6±7.0 years) walked at their self-selected slow, normal, and fast walking speeds on a 10 m walkway (ten trials/speed). Bilateral paired eight-electrode strips were horizontally aligned at mid-distance of the vertical line between greater trochanter and iliac crest. Concerning the ventral to dorsal direction, the center of each strip was placed on this vertical line. Initially, these signals were monopolarly sampled, but eight vertically oriented bipolar channels covering the whole gluteal region from ventral to dorsal (P1 to P8) were subsequently calculated by subtracting the signals of the corresponding electrodes of each electrode strip for both sides of the body. Three vertical bipolar channels represented the tensor fasciae latae (TFL; P2), gluteus medius (Gmed, SENIAM position; average of P4 and P5), and gluteus maximus muscles (Gmax; P7). To determine the interval between SEMG and corresponding GRF, the time delay (TD) between the respective first amplitude peaks (F1) in SEMG and vertical GRF curves was calculated. Results Throughout the grand averaged SEMG curves, the absolute amplitudes significantly differed among the three walking speeds at all electrode positions, with the amplitude of the F1 peak significantly increasing with increasing speed. In addition, when normalized to slow, the relative SEMG amplitude differences at the individual electrode positions showed an impressively homogeneous pattern. In both vertical GRF and all electrode SEMGs, the F1 peak occurred significantly earlier with increasing speed. Also, the TD between SEMG and vertical GRF F1 peaks significantly decreased with increasing speed. Concerning spatial activation, the TD between the respective F1 peaks in the SEMG and vertical GRF was significantly shorter for the ventral TFL position than the dorsal Gmed and Gmax positions, showing that the SEMG F1 peak during this initial phase of the gait cycle occurred earlier in the dorsal positions, and thus implying that the occurrence of the SEMG F1 peak proceeded from dorsal to ventral. Significance Tightly regulated spatial and temporal activation of the gluteal intermuscular functional unit, which includes both speed- and position-dependent mechanisms, seems to be an essential requirement for a functionally optimized, steady gait.
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Santos-Cuadros, Silvia, Sergio Fuentes del Toro, Ester Olmeda, and José Luis San Román. "Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?" Sensors 21, no. 16 (August 9, 2021): 5378. http://dx.doi.org/10.3390/s21165378.
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Deaths and serious injuries caused by traffic accidents is a concerning public health problem. However, the problem can be mitigated by the Autonomous Emergency Braking (AEB) system, which can avoid the impact. The market penetration of AEB is exponentially growing, and non-impact situations are expected to become more frequent. Thus, new injury patterns must be analysed, and the neck is particularly sensitive to sudden acceleration changes. Abrupt braking would be enough to be a potential risk for cervical spine injury. There is controversy about whether or not there are differences in cervical behaviour depending on whether passengers are relaxed or contract their muscles before the imminent accident. In the present manuscript, 18 volunteers were subjected to two different levels of awareness during an emergency braking test. Cervical muscles (sternocleidomastoid and trapezius) were analysed by the sEMG signal captured by means of a low-cost system. The differences observed in the muscle response according to gender and age were notable when passengers are warned. Gender differences were more significant in the post-braking phase. When passengers were relaxed, subjects older than 35 registered higher sEMG values. Meanwhile, when passengers contract their muscles, subjects who were younger than or equal to 35 years old experienced an increment in the values of the sEMG signals.
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Sangaboina, Swathi. "IOT Enabled Wearable Gloves with SEMG Subsystem with Posture Analysis." International Journal for Research in Applied Science and Engineering Technology 9, no. 9 (September 30, 2021): 1690–95. http://dx.doi.org/10.22214/ijraset.2021.38236.
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Abstract: Electromyogram (EMG) is a technique to track the record , analyze and estimate the electrical activity produced by muscles. This technique is used to detect the muscle issues that harm the nerves activity , muscle tissues and identify the location where they are joined together . This paper discusses the implementation of a project which can be considered as a tool for the acquisition of muscle activity, presentation and real-time attainment of EMG signal using a specific EMG sensor. The live EMG reading is recorded using the Wi-Fi- enabled Raspberrypi and then sent to a remote server in our case ThingSpeak server with the help of IoT concepts which helps in the telemetry of the obtained biomedical signals using the cloud. Results are displayed in ThingSpeak. The live recordings are also obtained on the PC using the serial plotter. This project can also help us in monitor and observe the progress of the patient treatment even if the physiotherapist could not come and data can be directly sent to them. Thus, the project aims to develop an EMG monitoring device based on IoT, for analyzing and acquiring EMG signals. Keywords: EMG sensor, Raspberry pi, LCD, ADS1115
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Lin, B., S. F. Wong, and A. Baca. "Comparison of Different Time-Frequency Analyses Techniques Based on sEMG-Signals in Table Tennis: A Case Study." International Journal of Computer Science in Sport 17, no. 1 (July 1, 2018): 77–93. http://dx.doi.org/10.2478/ijcss-2018-0004.
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Abstract The surface EMG signal in the action of dynamic contraction has more movement interference compared to sustained static contractions. In addition, the recruitment and de-recruitment of motor units causes a faster change in the surface EMG signal’s proprieties. Therefore, more complex techniques are required to extract information from the surface EMG signal. The standardized protocol for surface myoelectric signal measurement in table tennis was a case study in this research area. The Autoregressive method based on the Akaike Information Criterion, the Wavelet method based on intensity analysis, and the Hilbert-Huang transform method were used to estimate the muscle fatigue and non-fatigue condition. The result was that the Hilbert-Huang transform method was shown to be more reliable and accurate for studying the biceps brachii muscle in both conditions. However, the Wavelet method based on intensity analysis is more reliable and accurate for the pectoralis major muscle, deltoideus anterior muscle and deltoideus medialis muscle. The results suggest that different time-frequency analysis techniques influence different muscle analyses based on surface EMG signals in fatigue and non-fatigue conditions
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Toledo-Peral, Cinthya Lourdes, Gabriel Vega-Martínez, Jorge Airy Mercado-Gutiérrez, Gerardo Rodríguez-Reyes, Arturo Vera-Hernández, Lorenzo Leija-Salas, and Josefina Gutiérrez-Martínez. "Virtual/Augmented Reality for Rehabilitation Applications Using Electromyography as Control/Biofeedback: Systematic Literature Review." Electronics 11, no. 14 (July 20, 2022): 2271. http://dx.doi.org/10.3390/electronics11142271.
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Virtual reality (VR) and augmented reality (AR) are engaging interfaces that can be of benefit for rehabilitation therapy. However, they are still not widely used, and the use of surface electromyography (sEMG) signals is not established for them. Our goal is to explore whether there is a standardized protocol towards therapeutic applications since there are not many methodological reviews that focus on sEMG control/feedback. A systematic literature review using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) methodology is conducted. A Boolean search in databases was performed applying inclusion/exclusion criteria; articles older than 5 years and repeated were excluded. A total of 393 articles were selected for screening, of which 66.15% were excluded, 131 records were eligible, 69.46% use neither VR/AR interfaces nor sEMG control; 40 articles remained. Categories are, application: neurological motor rehabilitation (70%), prosthesis training (30%); processing algorithm: artificial intelligence (40%), direct control (20%); hardware: Myo Armband (22.5%), Delsys (10%), proprietary (17.5%); VR/AR interface: training scene model (25%), videogame (47.5%), first-person (20%). Finally, applications are focused on motor neurorehabilitation after stroke/amputation; however, there is no consensus regarding signal processing or classification criteria. Future work should deal with proposing guidelines to standardize these technologies for their adoption in clinical practice.
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Shibata, Akio, Junichiro Machida, Seishi Yamaguchi, Masashi Kimura, Tadashi Tatematsu, Hitoshi Miyachi, Atsuo Nakayama, Kazuo Shimozato, and Yoshihito Tokita. "Identification of nuclear localization signals in the human homeoprotein MSX1." Biochemistry and Cell Biology 96, no. 4 (August 2018): 483–89. http://dx.doi.org/10.1139/bcb-2017-0263.
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MSX1 is one of the homeoproteins with the homeodomain (HD) sequence, which regulates proliferation and differentiation of mesenchymal cells. In this study, we investigated the nuclear localization signal (NLS) in the MSX1 HD by deletion and amino acid substitution analyses. The web-based tool NLStradamus predicted 2 putative basic motifs in the N- and C-termini of the MSX1 HD. Green fluorescent protein (GFP) chimera studies revealed that NLS1 (161RKHKTNRKPR170) and NLS2 (216NRRAKAKR223) were independently insufficient for robust nuclear localization. However, they can work cooperatively to promote nuclear localization of MSX1, as was shown by the 2 tandem NLS motifs partially restoring functional NLS, leading to a significant nuclear accumulation of the GFP chimera. These results demonstrate a unique NLS motif in MSX1, which consists of an essential single core motif in helix-I, with weak potency, and an auxiliary subdomain in helix-III, which alone does not have nuclear localization potency. Additionally, other peptide sequences, other than predicted 2 motifs in the spacer, may be necessary for complete nuclear localization in MSX1 HD.
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Faria, J. P., V. Adibekyan, E. M. Amazo-Gómez, S. C. C. Barros, J. D. Camacho, O. Demangeon, P. Figueira, et al. "Decoding the radial velocity variations of HD 41248 with ESPRESSO." Astronomy & Astrophysics 635 (March 2020): A13. http://dx.doi.org/10.1051/0004-6361/201936389.
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Context. Twenty-four years after the discoveries of the first exoplanets, the radial-velocity (RV) method is still one of the most productive techniques to detect and confirm exoplanets. But stellar magnetic activity can induce RV variations large enough to make it difficult to disentangle planet signals from the stellar noise. In this context, HD 41248 is an interesting planet-host candidate, with RV observations plagued by activity-induced signals. Aims. We report on ESPRESSO observations of HD 41248 and analyse them together with previous observations from HARPS with the goal of evaluating the presence of orbiting planets. Methods. Using different noise models within a general Bayesian framework designed for planet detection in RV data, we test the significance of the various signals present in the HD 41248 dataset. We use Gaussian processes as well as a first-order moving average component to try to correct for activity-induced signals. At the same time, we analyse photometry from the TESS mission, searching for transits and rotational modulation in the light curve. Results. The number of significantly detected Keplerian signals depends on the noise model employed, which can range from 0 with the Gaussian process model to 3 with a white noise model. We find that the Gaussian process alone can explain the RV data while allowing for the stellar rotation period and active region evolution timescale to be constrained. The rotation period estimated from the RVs agrees with the value determined from the TESS light curve. Conclusions. Based on the data that is currently available, we conclude that the RV variations of HD 41248 can be explained by stellar activity (using the Gaussian process model) in line with the evidence from activity indicators and the TESS photometry.
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Cacciola, Matteo, Salvatore Calcagno, Filippo Laganà, Francesco Carlo Morabito, Diego Pellicanò, Isabella Palamara, Mario Versaci, and Biagio Cammaroto. "Wavelet and Unsupervised Learning Techniques for Experimental Biomedical Data Processing." International Journal of Measurement Technologies and Instrumentation Engineering 2, no. 3 (July 2012): 45–59. http://dx.doi.org/10.4018/ijmtie.2012070105.
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Learning theories and algorithms for both supervised and unsupervised Neural Networks (NNs) have already been accepted as relevant tools to cope with difficult problems based on the processing of experimental electromagnetic data. These kinds of problems are typically formulated as inverse problems. In this paper, in particular, the electrical signals under investigations derive from experimental electromyogram interference patterns measured on human subjects by means of non-invasive sensors (ElectroMyoGraphic, sEMS surface data). The monitoring and the analysis of dynamic sEMG data reveal important information on muscles activity and can be used by clinicians for both preventing dramatic illness evolution and improving athletes performances. The paper proposes the use of the Independent Component Analysis (ICA), an unsupervised learning technique, in order to process raw sEMG data by reducing the typical “cross-talk” effect on the electric interference pattern measured by the surface sensors. The ICA is implemented by means of a multi-layer NN scheme. Since the IC extraction is based on the assumption of stationarity of the involved sEMG recording, which is often inappropriate in the case of biomedical data, we also propose a technique for dealing with non-stationary recordings. The basic tool is the wavelet (time-frequency) decomposition, that allows us to detect and analyze time-varying signals. An auto-associative NN that exploits wavelet coefficients as an input vector is also used as simple detector of non-stationarity based on a measure of reconstruction error. The proposed approach not only yields encouraging results to the problem at hand, but suggests a general approach to solve similar relevant problems in some other experimental electromagnetics applications.
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Taube, Jeffrey S. "Interspike Interval Analyses Reveal Irregular Firing Patterns at Short, But Not Long, Intervals in Rat Head Direction Cells." Journal of Neurophysiology 104, no. 3 (September 2010): 1635–48. http://dx.doi.org/10.1152/jn.00649.2009.
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Previous studies have shown that a subset of neurons in the rat anterodorsal thalamus discharge as a function of the animal's head direction (HD) in the horizontal plane, independent of the animal's location and behavior. These cells have consistent firing properties across a wide range of conditions and cell discharge appears highly regular when listened to through a loudspeaker. In contrast, interspike interval (ISI) analyses on cortical cells have found that cell firing is irregular, even under constant stimulus conditions. Here, we analyzed HD cells from the anterodorsal thalamus, while rats foraged for food pellets, to determine whether their firing was regular or irregular. ISIs were measured when the animal's HD was maintained within ±6° of the cell's preferred firing direction. ISIs were highly variable with a mean coefficient of variation (CV) of 0.681. For each cell, the CV values at HDs ±24° away from the cell's preferred direction were similar to the coefficient measured at the cell's preferred direction. A second recording session showed that cells had similar coefficients of variation as the first session, suggesting that the degree of variability in cell spiking was a characteristic property for each cell. There was little correlation between ISIs and angular head velocity or translational speed. ISIs measured in HD cells from the postsubiculum and lateral mammillary nuclei showed higher CV values. These results indicate that despite the appearance of regularity in their firing, HD cells, like cortical cells, have irregular ISIs. In contrast to the irregular firing observed for ISIs, analyses over longer time intervals indicated that HD cell firing was much more regular, more nearly resembling a rate code. These findings have implications for attractor networks that model the HD signal and for models proposed to explain the generation of grid cell signals in entorhinal cortex.
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Wright, Galen E. B., Nicholas S. Caron, Bernard Ng, Lorenzo Casal, William Casazza, Xiaohong Xu, Jolene Ooi, et al. "Gene expression profiles complement the analysis of genomic modifiers of the clinical onset of Huntington disease." Human Molecular Genetics 29, no. 16 (August 15, 2020): 2788–802. http://dx.doi.org/10.1093/hmg/ddaa184.
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Abstract Huntington disease (HD) is a neurodegenerative disorder that is caused by a CAG repeat expansion in HTT. The length of this repeat, however, only explains a proportion of the variability in age of onset in patients. Genome-wide association studies have identified modifiers that contribute toward a proportion of the observed variance. By incorporating tissue-specific transcriptomic information with these results, additional modifiers can be identified. We performed a transcriptome-wide association study assessing heritable differences in genetically determined expression in diverse tissues, with genome-wide data from over 4000 patients. Functional validation of prioritized genes was undertaken in isogenic HD stem cells and patient brains. Enrichment analyses were performed with biologically relevant gene sets to identify the core pathways. HD-associated gene coexpression modules were assessed for associations with neurological phenotypes in an independent cohort and to guide drug repurposing analyses. Transcriptomic analyses identified genes that were associated with age of HD onset and displayed colocalization with gene expression signals in brain tissue (FAN1, GPR161, PMS2, SUMF2), with supporting evidence from functional experiments. This included genes involved in DNA repair, as well as novel-candidate modifier genes that have been associated with other neurological conditions. Further, cortical coexpression modules were also associated with cognitive decline and HD-related traits in a longitudinal cohort. In summary, the combination of population-scale gene expression information with HD patient genomic data identified novel modifier genes for the disorder. Further, these analyses expanded the pathways potentially involved in modifying HD onset and prioritized candidate therapeutics for future study.
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Solomon, Nancy Pearl, and Benjamin Munson. "The Effect of Jaw Position on Measures of Tongue Strength and Endurance." Journal of Speech, Language, and Hearing Research 47, no. 3 (June 2004): 584–94. http://dx.doi.org/10.1044/1092-4388(2004/045).
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Assessment of tongue strength and endurance is common in research and clinical contexts. It is unclear whether the results reveal discrete function by the tongue or combined abilities of the tongue and jaw. One way to isolate the movement of the tongue is to constrain the jaw kinematically by using a bite block. In this study, 10 neurologically normal young adults performed tongue strength and endurance tasks without a bite block ("jaw-free") and with bite blocks of various heights (2, 5, 10, and 15 mm for strength; 5 mm for endurance). Data signals included tongue pressure exerted on an air-filled bulb, surface electromyography (SEMG) from the superior tongue blade, and SEMG from 1 masseter. On average, tongue strength (pressure in kPa) was greatest with no bite block and generally decreased as bite blocks increased in height. Pairwise analyses revealed statistically significant differences for all but 3 comparisons (jaw-free to 2 mm, 2 to 5 mm, and 5 to 10 mm). After removing outlying data from 1 participant, tongue endurance at 50% of tongue strength was significantly greater without a bite block than with one. SEMG data did not differ significantly for the strength task across bite block conditions, but inspection of the individual data revealed a tendency for masseter activity to be lower when the jaw was unconstrained. These results suggest that maximal tongue strength and endurance are best assessed with an unconstrained mandible or with a very small bite block.
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Liu, An-Bang, and Che-Wei Lin. "Multiscale Approximate Entropy for Gait Analysis in Patients with Neurodegenerative Diseases." Entropy 21, no. 10 (September 25, 2019): 934. http://dx.doi.org/10.3390/e21100934.
Full textAbstract:
Neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson’s diseases (PD), and Huntington’s disease (HD) are not rare neurological diseases. They affect different neurological systems and present various characteristic gait abnormalities. We retrieved gait signals of the right and left feet from a public domain on the Physionet. There were 13 patients with ALS, 15 patients with PD, 20 patients with HD and 16 healthy controls (HC). We used multiscale approximate entropy (MAE) to analyze ground reaction force on both feet. Our study shows that MAE increases with scales in all tested subjects. The group HD has the highest MAE and group ALS has the lowest MAE. We can differentiate ALS from HC by MAE, while scale factors >10 in the left foot. There are few significant differences of MAE between the HC and HD. We found a good correlation of MAE between both feet in group ALS. In conclusion, our results indicate that MAE analysis of gait signals can be used for diagnosis and long-term assessment for ALS and probably HD. Similarity of MAE between both feet can also be a diagnostic marker for ALS.
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Jäckel, David, Urs Frey, Michele Fiscella, Felix Franke, and Andreas Hierlemann. "Applicability of independent component analysis on high-density microelectrode array recordings." Journal of Neurophysiology 108, no. 1 (July 1, 2012): 334–48. http://dx.doi.org/10.1152/jn.01106.2011.
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Emerging complementary metal oxide semiconductor (CMOS)-based, high-density microelectrode array (HD-MEA) devices provide high spatial resolution at subcellular level and a large number of readout channels. These devices allow for simultaneous recording of extracellular activity of a large number of neurons with every neuron being detected by multiple electrodes. To analyze the recorded signals, spiking events have to be assigned to individual neurons, a process referred to as “spike sorting.” For a set of observed signals, which constitute a linear mixture of a set of source signals, independent component (IC) analysis (ICA) can be used to demix blindly the data and extract the individual source signals. This technique offers great potential to alleviate the problem of spike sorting in HD-MEA recordings, as it represents an unsupervised method to separate the neuronal sources. The separated sources or ICs then constitute estimates of single-neuron signals, and threshold detection on the ICs yields the sorted spike times. However, it is unknown to what extent extracellular neuronal recordings meet the requirements of ICA. In this paper, we evaluate the applicability of ICA to spike sorting of HD-MEA recordings. The analysis of extracellular neuronal signals, recorded at high spatiotemporal resolution, reveals that the recorded data cannot be modeled as a purely linear mixture. As a consequence, ICA fails to separate completely the neuronal signals and cannot be used as a stand-alone method for spike sorting in HD-MEA recordings. We assessed the demixing performance of ICA using simulated data sets and found that the performance strongly depends on neuronal density and spike amplitude. Furthermore, we show how postprocessing techniques can be used to overcome the most severe limitations of ICA. In combination with these postprocessing techniques, ICA represents a viable method to facilitate rapid spike sorting of multidimensional neuronal recordings.
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Xie, Ping, Qingya Chang, Yuanyuan Zhang, Xiaojiao Dong, Jinxu Yu, and Xiaoling Chen. "Estimation of Time-Frequency Muscle Synergy in Wrist Movements." Entropy 24, no. 5 (May 16, 2022): 707. http://dx.doi.org/10.3390/e24050707.
Full textAbstract:
Muscle synergy analysis is a kind of modularized decomposition of muscles during exercise controlled by the central nervous system (CNS). It can not only extract the synergistic muscles in exercise, but also obtain the activation states of muscles to reflect the coordination and control relationship between muscles. However, previous studies have mainly focused on the time-domain synergy without considering the frequency-specific characteristics within synergy structures. Therefore, this study proposes a novel method, named time-frequency non-negative matrix factorization (TF-NMF), to explore the time-varying regularity of muscle synergy characteristics of multi-channel surface electromyogram (sEMG) signals at different frequency bands. In this method, the wavelet packet transform (WPT) is used to transform the time-scale signals into time-frequency dimension. Then, the NMF method is calculated in each time-frequency window to extract the synergy modules. Finally, this method is used to analyze the sEMG signals recorded from 8 muscles during the conversion between wrist flexion (WF stage) and wrist extension (WE stage) movements in 12 healthy people. The experimental results show that the number of synergy modules in wrist flexion transmission to wrist extension (Motion Conversion, MC stage) is more than that in the WF stage and WE stage. Furthermore, the number of flexor and extensor muscle synergies in the frequency band of 0–125 Hz during the MC stage is more than that in the frequency band of 125–250 Hz. Further analysis shows that the flexion muscle synergies mostly exist in the frequency band of 140.625–156.25 Hz during the WF stage, and the extension muscle synergies appear in the frequency band of 125–156.25 Hz during the WE stage. These results can help to better understand the time-frequency features of muscle synergy, and expand study perspective related to motor control in nervous system.
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Bassett, Joshua P., Michaël B. Zugaro, Gary M. Muir, Edward J. Golob, Robert U. Muller, and Jeffrey S. Taube. "Passive Movements of the Head Do Not Abolish Anticipatory Firing Properties of Head Direction Cells." Journal of Neurophysiology 93, no. 3 (March 2005): 1304–16. http://dx.doi.org/10.1152/jn.00490.2004.
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Neurons in the anterior dorsal thalamic nucleus (ADN) of the rat selectively discharge in relation to the animal's head direction (HD) in the horizontal plane. Temporal analyses of cell firing properties reveal that their discharge is optimally correlated with the animal's future directional heading by ∼24 ms. Among the hypotheses proposed to explain this property is that ADN HD cells are informed of future head movement via motor efference copy signals. One prediction of this hypothesis is that when the rat's head is moved passively, the anticipatory time interval (ATI) will be attenuated because the motor efference signal reflects only the active contribution to the movement. The present study tested this hypothesis by loosely restraining the animal and passively rotating it through the cell's preferred direction. Contrary to our prediction, we found that ATI values did not decrease during passive movement but in fact increased significantly. HD cells in the postsubiculum did not show the same effect, suggesting independence between the two sites with respect to anticipatory firing. We conclude that it is unlikely that a motor efference copy signal alone is responsible for generating anticipatory firing in ADN HD cells.
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Yaqub, M. Atif, Seong-Woo Woo, and Keum-Shik Hong. "Effects of HD-tDCS on Resting-State Functional Connectivity in the Prefrontal Cortex: An fNIRS Study." Complexity 2018 (November 1, 2018): 1–13. http://dx.doi.org/10.1155/2018/1613402.
Full textAbstract:
Functional connectivity is linked to several degenerative brain diseases prevalent in our aging society. Electrical stimulation is used for the clinical treatment and rehabilitation of patients with many cognitive disorders. In this study, the effects of high-definition transcranial direct current stimulation (HD-tDCS) on resting-state brain networks in the human prefrontal cortex were investigated by using functional near-infrared spectroscopy (fNIRS). The intrahemispheric as well as interhemispheric connectivity changes induced by 1 mA HD-tDCS were examined in 15 healthy subjects. Pearson correlation coefficient-based correlation matrices were generated from filtered time series oxyhemoglobin (ΔHbO) signals and converted into binary matrices. Common graph theory metrics were computed to evaluate the network changes. Systematic interhemispheric, intrahemispheric, and intraregional connectivity analyses demonstrated that the stimulation positively affected the resting-state connectivity in the prefrontal cortex. The poststimulation connectivity was increased throughout the prefrontal region, while focal HD-tDCS effects induced an increased rate of connectivity in the stimulated hemisphere. The graph theory metrics clearly distinguished the prestimulation and poststimulation networks for a range of thresholds. The results of this study suggest that HD-tDCS can be used to increase functional connectivity in the prefrontal cortex. The increase in functional connectivity can be explored clinically for neurorehabilitation of patients with degenerative brain diseases.
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Püsküllü, Çağlar, and Faruk Soydugan. "Analysis of ground-based observations of some exoplanets." Canadian Journal of Physics 96, no. 7 (July 2018): 681–84. http://dx.doi.org/10.1139/cjp-2017-0780.
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We present analyses of the transit light curves and transit time measurements of the exoplanets HAT-P-3b, HD 189733b, and WASP-43b. Transit light curves were collected at Çanakkale Onsekiz Mart University Observatory and TÜBİTAK National Observatory. The models were produced by WINFITTER code and stellar, planetary, and orbital properties were obtained and discussed. We searched for significant signals at the O-C diagrams generated with our transit times and additional data based on Exoplanet Transit Database.
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Leone, Alessandro, Gabriele Rescio, Andrea Manni, Pietro Siciliano, and Andrea Caroppo. "Comparative Analysis of Supervised Classifiers for the Evaluation of Sarcopenia Using a sEMG-Based Platform." Sensors 22, no. 7 (April 1, 2022): 2721. http://dx.doi.org/10.3390/s22072721.
Full textAbstract:
Sarcopenia is a geriatric condition characterized by a loss of strength and muscle mass, with a high impact on health status, functional independence and quality of life in older adults. [d=TT, ]To reduce the effects of the disease, just the diagnostic is not enough, it is necessary more than recognition.To reduce the effects of the disease, it is important to recognize the level and progression of sarcopenia early. Surface electromyography is becoming increasingly relevant for the prevention and diagnosis of sarcopenia, also due to a wide diffusion of smart and minimally invasive wearable devices suitable for electromyographic monitoring. The purpose of this work is manifold. The first aim is the design and implementation of a hardware/software platform. It is based on the elaboration of surface electromyographic signals extracted from the Gastrocnemius Lateralis and Tibialis Anterior muscles, useful to analyze the strength of the muscles with the purpose of distinguishing three different “confidence” levels of sarcopenia. The second aim is to compare the efficiency of state of the art supervised classifiers in the evaluation of sarcopenia. The experimentation stage was performed on an “augmented” dataset starting from data acquired from 32 patients. The latter were distributed in an unbalanced manner on 3 “confidence” levels of sarcopenia. The obtained results in terms of classification accuracy demonstrated the ability of the proposed platform to distinguish different sarcopenia “confidence” levels, with highest accuracy value given by Support Vector Machine classifier, outperforming the other classifiers by an average of 7.7%.
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Cai, Yanling, Ezra S. Bartholomew, Mingming Dong, Xuling Zhai, Shuai Yin, Yaqi Zhang, Zhongxuan Feng, et al. "The HD-ZIP IV transcription factor GL2-LIKE regulates male flowering time and fertility in cucumber." Journal of Experimental Botany 71, no. 18 (June 3, 2020): 5425–37. http://dx.doi.org/10.1093/jxb/eraa251.
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Abstract Cucumber is dioecious by nature, having both male and female flowers, and is a model system for unisexual flower development. Knowledge related to male flowering is limited, but it is reported to be regulated by transcription factors and hormone signals. Here, we report functional characterization of the cucumber (Cucumis sativus) GL2-LIKE gene, which encodes a homeodomain leucine zipper (HD-ZIP) IV transcription factor that plays an important role in regulating male flower development. Spatial–temporal expression analyses revealed high-level expression of CsGL2-LIKE in the male flower buds and anthers. CsGL2-LIKE is closely related to AtGL2, which is known to play a key role in trichome development. However, ectopic expression of CsGL2-LIKE in Arabidopsis gl2-8 mutant was unable to rescue the gl2-8 phenotype. Interestingly, the silencing of CsGL2-LIKE delayed male flowering by inhibiting the expression of the florigen gene FT and reduced pollen vigor and seed viability. Protein–protein interaction assays showed that CsGL2-LIKE interacts with the jasmonate ZIM domain protein CsJAZ1 to form a HD-ZIP IV–CsJAZ1 complex. Collectively, our study indicates that CsGL2-LIKE regulates male flowering in cucumber, and reveals a novel function of a HD-ZIP IV transcription factor in regulating male flower development of cucumber.
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Dumusque, Xavier, Oliver Turner, Caroline Dorn, Jason D. Eastman, Romain Allart, Vardan Adibekyan, Sergio Sousa, et al. "Hot, rocky and warm, puffy super-Earths orbiting TOI-402 (HD 15337)." Astronomy & Astrophysics 627 (June 28, 2019): A43. http://dx.doi.org/10.1051/0004-6361/201935457.
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Context. The Transiting Exoplanet Survey Satellite (TESS) is revolutionising the search for planets orbiting bright and nearby stars. In sectors 3 and 4, TESS observed TOI-402 (TIC-120896927), a bright V = 9.1 K1 dwarf also known as HD 15337, and found two transiting signals with periods of 4.76 and 17.18 days and radii of 1.90 and 2.21 R⊕, respectively. This star was observed prior to the TESS detection as part of the radial-velocity (RV) search for planets using the HARPS spectrometer, and 85 precise RV measurements were obtained before the launch of TESS over a period of 14 yr. Aims. In this paper, we analyse the HARPS RV measurements in hand to confirm the planetary nature of these two signals. Methods. HD 15337 happens to present a stellar activity level similar to the Sun, with a magnetic cycle of similar amplitude and RV measurements that are affected by stellar activity. By modelling this stellar activity in the HARPS radial velocities using a linear dependence with the calcium activity index log(RHK′), we are able, with a periodogram approach, to confirm the periods and the planetary nature of TOI-402.01 and TOI-402.02. We then derive robust estimates from the HARPS RVs for the orbital parameters of these two planets by modelling stellar activity with a Gaussian process and using the marginalised posterior probability density functions obtained from our analysis of TESS photometry for the orbital period and time of transit. Results. By modelling TESS photometry and the stellar host characteristics, we find that TOI-402.01 and TOI-402.02 have periods of 4.75642 ± 0.00021 and 17.1784 ± 0.0016 days and radii of 1.70 ± 0.06 and 2.52 ± 0.11 R⊕ (precision 3.6 and 4.2%), respectively. By analysing the HARPS RV measurements, we find that those planets are both super-Earths with masses of 7.20 ± 0.81 and 8.79 ± 1.68 M⊕ (precision 11.3 and 19.1%), and small eccentricities compatible with zero at 2σ. Conclusions. Although having rather similar masses, the radii of these two planets are very different, putting them on different sides of the radius gap. By studying the temporal evolution under X-ray and UV (XUV) driven atmospheric escape of the TOI-402 planetary system, we confirm, under the given assumptions, that photo-evaporation is a plausible explanation for this radius difference. Those two planets, being in the same system and therefore being in the same irradiation environment are therefore extremely useful for comparative exoplanetology across the evaporation valley and thus bring constraints on the mechanisms responsible for the radius gap.
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Ogden, Tom E. H., Ji-Chun Yang, Marianne Schimpl, Laura E. Easton, Elizabeth Underwood, Philip B. Rawlins, Michael M. McCauley, et al. "Dynamics of the HD regulatory subdomain of PARP-1; substrate access and allostery in PARP activation and inhibition." Nucleic Acids Research 49, no. 4 (January 28, 2021): 2266–88. http://dx.doi.org/10.1093/nar/gkab020.
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Abstract PARP-1 is a key early responder to DNA damage in eukaryotic cells. An allosteric mechanism links initial sensing of DNA single-strand breaks by PARP-1’s F1 and F2 domains via a process of further domain assembly to activation of the catalytic domain (CAT); synthesis and attachment of poly(ADP-ribose) (PAR) chains to protein sidechains then signals for assembly of DNA repair components. A key component in transmission of the allosteric signal is the HD subdomain of CAT, which alone bridges between the assembled DNA-binding domains and the active site in the ART subdomain of CAT. Here we present a study of isolated CAT domain from human PARP-1, using NMR-based dynamics experiments to analyse WT apo-protein as well as a set of inhibitor complexes (with veliparib, olaparib, talazoparib and EB-47) and point mutants (L713F, L765A and L765F), together with new crystal structures of the free CAT domain and inhibitor complexes. Variations in both dynamics and structures amongst these species point to a model for full-length PARP-1 activation where first DNA binding and then substrate interaction successively destabilise the folded structure of the HD subdomain to the point where its steric blockade of the active site is released and PAR synthesis can proceed.
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Alonso-Floriano, F. J., A. Sánchez-López, I. A. G. Snellen, M. López-Puertas, E. Nagel, P. J. Amado, F. F. Bauer, et al. "Multiple water band detections in the CARMENES near-infrared transmission spectrum of HD 189733 b." Astronomy & Astrophysics 621 (January 2019): A74. http://dx.doi.org/10.1051/0004-6361/201834339.
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Aims. We explore the capabilities of CARMENES for characterising hot-Jupiter atmospheres by targeting multiple water bands, in particular, those at 1.15 and 1.4 μm. Hubble Space Telescope observations suggest that this wavelength region is relevant for distinguishing between hazy and/or cloudy and clear atmospheres. Methods. We observed one transit of the hot Jupiter HD 189733 b with CARMENES. Telluric and stellar absorption lines were removed using SYSREM, which performs a principal component analysis including proper error propagation. The residual spectra were analysed for water absorption with cross-correlation techniques using synthetic atmospheric absorption models. Results. We report a cross-correlation peak at a signal-to-noise ratio (S/N) of 6.6, revealing the presence of water in the transmission spectrum of HD 189733 b. The absorption signal appeared slightly blueshifted at –3.9 ± 1.3 km s−1. We measured the individual cross-correlation signals of the water bands at 1.15 and 1.4 μm, finding cross-correlation peaks at S/N of 4.9 and 4.4, respectively. The 1.4 μm feature is consistent with that observed with the Hubble Space Telescope. Conclusions. The water bands studied in this work have been mainly observed in a handful of planets from space. Being able also to detect them individually from the ground at higher spectral resolution can provide insightful information to constrain the properties of exoplanet atmospheres. Although the current multi-band detections can not yet constrain atmospheric haze models for HD 189733 b, future observations at higher S/N could provide an alternative way to achieve this aim.
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Li, Bo, Bo Yuan, Shuai Tang, Yuwen Mao, Dongmei Zhang, Changyun Huang, and Bilian Tan. "Biomechanical design analysis and experiments evaluation of a passive knee-assisting exoskeleton for weight-climbing." Industrial Robot: An International Journal 45, no. 4 (June 18, 2018): 436–45. http://dx.doi.org/10.1108/ir-11-2017-0207.
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Purpose This paper aims to investigate weight-climbing assistance strategy for the biomechanical design of passive knee-assisting exoskeleton (PKAExo) and evaluate a designed PKAExo which stores energy when the knee joint flexes and releases the energy to assist ascending when the knee joint extends. Design/methodology/approach The authors constructed theoretic modeling of human weight-climbing to analyze characteristics of knee angle and moment. They then conducted camera-based movement analysis, muscle strength and endurance tests and surface electromyography (sEMG) measures to verify the relationship of knee angle and moment with both stair height and load weight. Afterwards, the authors proposed an assistant strategy for passive knee assistance, then gave out designed PKAExo and conducted mechanical experiment to test the knee-assisting torque. Finally, the authors conducted comparison experiment based on measuring the sEMG signals of knee extensor to verify the assistance effect of the PKAExo for weight-climbing. Findings The knee extensor produces the maximum force during weight-climbing, and the muscle force provided by knee extensor has significant increasing rate along with the stair height. Thus, the assistance torque of PKAExo is designed to increase nonlinearly along with increasing knee angle. It stores energy when knee flexes and assists when knee extends. Both the mechanical experiment and comparison experiment have demonstrated that the PKAExo is able to provide nonlinear assistance torque for weight-climbing, thus decreasing the average maximum load of knee extensor by about 21 per cent, reducing muscle fatigue and enhancing wearer’s weight-climbing ability. Originality/value The authors construct theoretic maximum force model produced by knee extensor for weight-climbing in static situation and conduct a series of experiments to verify and revise the model, which is the fundamental reference for knee-assisting mechanism designed for weight-climbing. The authors have also provided and validated an assistant strategy and the mechanism based on the biomechanical analysis, which aims to translate wearer’s energy-providing mode form high load to mid-low load by storing energy when knee flexes and assisting when knee extends. The PKAExo decreases the maximum load of knee extensor, reduces muscle fatigue and helps people to easily climb with load.
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Yu, Binbin, Xintong Zhang, Yihui Cheng, Lingling Liu, YanJiang, Jiayue Wang, and Xiao Lu. "The Effects of the Biceps Brachii and Brachioradialis on Elbow Flexor Muscle Strength and Spasticity in Stroke Patients." Neural Plasticity 2022 (March 2, 2022): 1–15. http://dx.doi.org/10.1155/2022/1295908.
Full textAbstract:
Objective. Muscle weakness and spasticity are common consequences of stroke, leading to a decrease in physical activity. The effective implementation of precision rehabilitation requires detailed rehabilitation evaluation. We aimed to analyze the surface electromyography (sEMG) signal features of elbow flexor muscle (biceps brachii and brachioradialis) spasticity in maximum voluntary isometric contraction (MVIC) and fast passive extension (FPE) in stroke patients and to explore the main muscle groups that affect the active movement and spasticity of the elbow flexor muscles to provide an objective reference for optimizing stroke rehabilitation. Methods. Fifteen patients with elbow flexor spasticity after stroke were enrolled in this study. sEMG signals of the paretic and nonparetic elbow flexor muscles (biceps and brachioradialis) were detected during MVIC and FPE, and root mean square (RMS) values were calculated. The RMS values (mean and peak) of the biceps and brachioradialis were compared between the paretic and nonparetic sides. Additionally, the correlation between the manual muscle test (MMT) score and the RMS values (mean and peak) of the paretic elbow flexors during MVIC was analyzed, and the correlation between the modified Ashworth scale (MAS) score and the RMS values (mean and peak) of the paretic elbow flexors during FPE was analyzed. Results. During MVIC exercise, the RMS values (mean and peak) of the biceps and brachioradialis on the paretic side were significantly lower than those on the nonparetic side ( p < 0.01 ), and the RMS values (mean and peak) of the bilateral biceps were significantly higher than those of the brachioradialis ( p < 0.01 ). The MMT score was positively correlated with the mean and peak RMS values of the paretic biceps and brachioradialis ( r = 0.89 , r = 0.91 , r = 0.82 , r = 0.85 ; p < 0.001 ). During FPE exercise, the RMS values (mean and peak) of the biceps and brachioradialis on the paretic side were significantly higher than those on the nonparetic side ( p < 0.01 ), and the RMS values (mean and peak) of the brachioradialis on the paretic side were significantly higher than those of the biceps ( p < 0.01 ). TheMAS score was positively correlated with the mean RMS of the paretic biceps and brachioradialis ( r = 0.62 , p = 0.021 ; r = 0.74 , p = 0.004 ), and the MAS score was positively correlated with the peak RMS of the paretic brachioradialis ( r = 0.59 , p = 0.029 ) but had no significant correlation with the peak RMS of the paretic biceps ( r = 0.49 , p > 0.05 ). Conclusions. The results confirm that the biceps is a vital muscle in active elbow flexion and that the brachioradialis plays an important role in elbow flexor spasticity, suggesting that the biceps should be the focus of muscle strength training of the elbow flexors and that the role of the brachioradialis should not be ignored in the treatment of elbow flexor spasticity. This study also confirmed the application value of sEMG in the objective assessment of individual muscle strength and spasticity in stroke patients.
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Marcos-Antón, Selena, María Dolores Gor-García-Fogeda, and Roberto Cano-de-la-Cuerda. "An sEMG-Controlled Forearm Bracelet for Assessing and Training Manual Dexterity in Rehabilitation: A Systematic Review." Journal of Clinical Medicine 11, no. 11 (May 31, 2022): 3119. http://dx.doi.org/10.3390/jcm11113119.
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Background: The ability to perform activities of daily living (ADL) is essential to preserving functional independence and quality of life. In recent years, rehabilitation strategies based on new technologies, such as MYO Armband®, have been implemented to improve dexterity in people with upper limb impairment. Over the last few years, many studies have been published focusing on the accuracy of the MYO Armband® to capture electromyographic and inertial data, as well as the clinical effects of using it as a rehabilitation tool in people with loss of upper limb function. Nevertheless, to our knowledge, there has been no systematic review of this subject. Methods: A systematically comprehensive literature search was conducted in order to identify original studies that answered the PICO question (patient/population, intervention, comparison, and outcome): What is the accuracy level and the clinical effects of the MYO Armband® in people with motor impairment of the upper limb compared with other assessment techniques or interventions or no intervention whatsoever? The following data sources were used: Pubmed, Scopus, Web of Science, ScienceDirect, Physiotherapy Evidence Database, and the Cochrane Library. After identifying the eligible articles, a cross-search of their references was also completed for additional studies. The following data were extracted from the papers: study design, disease or condition, intervention, sample, dosage, outcome measures or data collection procedure and data analysis and results. The authors independently collected these data following the CONSORT 2010 statement when possible, and eventually reached a consensus on the extracted data, resolving disagreements through discussion. To assess the methodological quality of papers included, the tool for the critical appraisal of epidemiological cross-sectional studies was used, since only case series studies were identified after the search. Additionally, the articles were classified according to the levels of evidence and grades of recommendation for diagnosis studies established by the Oxford Center for Evidence-Based Medicine. Also, The Cochrane Handbook for Systematic Reviews of Interventions was used by two independent reviewers to assess risk of bias, assessing the six different domains. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was followed to carry out this review. Results: 10 articles with a total 180 participants were included in the review. The characteristics of included studies, sample and intervention characteristics, outcome measures, the accuracy of the system and effects of the interventions and the assessment of methodological quality of the studies and risk of bias are shown. Conclusions: Therapy with the MYO Armband® has shown clinical changes in range of motion, dexterity, performance, functionality and satisfaction. It has also proven to be an accurate system to capture signals from the forearm muscles in people with motor impairment of the upper limb. However, further research should be conducted using bigger samples, well-defined protocols, comparing with control groups or comparing with other assessment or therapeutic tools, since the studies published so far present a high risk of bias and low level of evidence and grade of recommendation.
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Schwartz-Cornil, Isabelle, Michel Bonneau, Marc Dalod, and Nicolas Bertho. "IMPACT OF LARGE MAMMALS MODELS IN IMMUNOLOGY." Reproduction, Fertility and Development 24, no. 1 (2012): 287. http://dx.doi.org/10.1071/rdv24n1ab250.
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Immune responses that control tolerance to self, tolerance to conceptus during pregnancy, and defense against cancer and pathogens are governed by dendritic cells (DC), that are key immune cell types that integrate environment signals and direct T and B cell immune responses. Different DC subtypes exist in mice that each trigger a specific type of immune response, such as cytotoxicity, antibody production, and regulatory processes. Interestingly in mice, it is possible to target specific DC subtypes with antigenised antibodies and obtain a desired type of immune response. However this conceptual breakthrough in vaccinology and immune regulation manipulation may only be valid for laboratory mice, as unfortunately often encountered in the process of bench to bed side translation. Furthermore, whether DC subsets knowledge and manipulation can be translated to human and to animal of socio-economical importance is still not known. We adressed this question in pigs and ruminants. The interest of these species over mice are that (1) they are the direct target species for vaccines, (2) they present genetic diversities and live in an open environment, (3) they present physiological similarities with human such as skin for pigs with skin being a main site for vaccination, (4) skin migrated DC and DC subsets can be collected from lymph after surgical catheterisation of lymph ducts in these species, and not in mice. We studied the molecular characterisation profiles of DC subsets from skin in ruminant and swine and evaluated how they compare to mouse and human DC subsets, based on comparative transcriptomic analyses. We assessed whether ruminant and swine DC subsets share functional similarities and differences with the corresponding murine subsets, and whether these properties translate into novel vaccine developements. Overall our work unravel conserved molecular and functional features that allow characterization of dendritic cell subtypes across mammals and possibly across vertebrates. In the past few decades, a tremendous amount of effort has been invested in developing gene and cell therapies for inherited genetic diseases such as Huntington's disease (HD). However, progress in their clinical application has been very limited. One of the major barriers is the lack of appropriate animal models that allow precise prediction patterns in human patients. Most of the animal models used for gene and cell therapy study are primarily focused on safety and toxicity evaluation, while therapeutic efficacy cannot be fully addressed because they do not carry the same human diseases. Although mouse models of human diseases are available and have been widely used for the development of new therapies, mice are not good predictors for humans because of the fundamental differences (genome composition, body size, life span and metabolic mechanism) between humans and rodents. Although monkeys are one of the best models for studying pharmacokinetics and overall impact of treatment, they are primarily used for safety and toxicity evaluation. Even HD monkey models, created by chemical induction or focal gene transfer in the brain, develop similar cellular pathology, therapeutic efficacy and systemic evaluation cannot be determined, which is one of the major barriers in drug and therapeutic development. The development of transgenic HD monkeys has opened the door for a new paradigm of animal modeling for the advancement of novel gene and cell therapy. HD monkeys not only carry the genetic defect that leads to human HD, they also develop clinical features comparable to humans that no other animal model does. While testing in HD monkeys has yet to be achieved until a cohort of well characterized HD monkeys was established, iPS cell lines derived from HD monkeys with a board spectrum of HD pathology and clinical features are a unique in vitro model for studying HD pathogenesis and the development of novel therapeutic approaches. New knowledge and treatments generated from iPS cells can next be translated and applied in HD monkeys from whom the stem cells were derived, thus the goal of personalized medicine can also be evaluated. This work was funded by a grant from NCRR/NIH (R24RR018827).
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Massaroni, Carlo, Daniel Simões Lopes, Daniela Lo Presti, Emiliano Schena, and Sergio Silvestri. "Contactless Monitoring of Breathing Patterns and Respiratory Rate at the Pit of the Neck: A Single Camera Approach." Journal of Sensors 2018 (September 23, 2018): 1–13. http://dx.doi.org/10.1155/2018/4567213.
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Vital signs monitoring is pivotal not only in clinical settings but also in home environments. Remote monitoring devices, systems, and services are emerging as tracking vital signs must be performed on a daily basis. Different types of sensors can be used to monitor breathing patterns and respiratory rate. However, the latter remains the least measured vital sign in several scenarios due to the intrusiveness of most adopted sensors. In this paper, we propose an inexpensive, off-the-shelf, and contactless measuring system for respiration signals taking as region of interest the pit of the neck. The system analyses video recorded by a single RGB camera and extracts the respiratory pattern from intensity variations of reflected light at the level of the collar bones and above the sternum. Breath-by-breath respiratory rate is then estimated from the processed breathing pattern. In addition, the effect of image resolution on monitoring breathing patterns and respiratory rate has been investigated. The proposed system was tested on twelve healthy volunteers (males and females) during quiet breathing at different sensor resolution (i.e., HD 720, PAL, WVGA, VGA, SVGA, and NTSC). Signals collected with the proposed system have been compared against a reference signal in both the frequency domain and time domain. By using the HD 720 resolution, frequency domain analysis showed perfect agreement between average breathing frequency values gathered by the proposed measuring system and reference instrument. An average mean absolute error (MAE) of 0.55 breaths/min was assessed in breath-by-breath monitoring in the time domain, while Bland-Altman showed a bias of −0.03 ± 1.78 breaths/min. Even in the case of lower camera resolution setting (i.e., NTSC), the system demonstrated good performances (MAE of 1.53 breaths/min, bias of −0.06 ± 2.08 breaths/min) for contactless monitoring of both breathing pattern and breath-by-breath respiratory rate over time.
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Palma, Marzia, Giusy Gentilcore, Fariba Mozaffari, Kia Heimersson, Barbro Näsman-Glaser, Lotta Hansson, Anders Österborg, and Håkan Mellstedt. "T Cells from Chronic Lymphocytic Leukemia (CLL) Patients Display Dysregulated Expression of Immune Checkpoint Molecules and Activation Markers Mainly Restricted to CD4+ Cells and Correlated with Disease Activity." Blood 126, no. 23 (December 3, 2015): 4132. http://dx.doi.org/10.1182/blood.v126.23.4132.4132.
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Abstract Background CLL patients (pts) have impaired humoral and cellular immune functions, which is largely due to profound defects of T-cells. Regulation and activation of T lymphocytes depend not only on T cell receptor signaling but also on co-signaling receptors delivering either inhibitory or stimulatory signals, known as immune checkpoints. CTLA-4 (cytotoxic T lymphocyte-associated antigen-4) is transiently expressed on activated T cells, binding the same ligands as CD28, inhibiting T-cell activation. Similarly, programmed cell death protein 1 (PD-1) is expressed on activated CD4+ and CD8+ T cells inhibiting T-cell functions upon binding to the ligands B7-H1 (PD-L1, CD274) and B7-DC (PD-L2, CD273). CD137 is an inducible costimulatory receptor expressed by activated T cells. Dysregulated expression of immune checkpoint receptors on T cells of CLL pts may have an impact on T-cell responsiveness and might be a mechanism for the immune deficiency in the disease. Aim To evaluate the expression of the immune checkpoint molecules CTLA-4, PD-1 and CD137 as well as of the cell proliferation marker Ki67, the activation marker CD69 and of CD103, a marker expressed on regulatory T cells, in T cells from CLL pts in different disease phases. Methods Peripheral blood samples were obtained from 69 CLL pts and 13 healthy control donors (HD). Pts were sub-grouped according to disease phase: indolent vs progressive (i.e. fulfilling criteria for active disease). The expression of CTLA-4, PD-1, PD-L1, CD69, CD103, CD137 and Ki-67 was assessed by flow-cytometry on CD4+ and CD8+ T cells. We also analysed the change in expression of these markers on T cells after 72 hours of PHA stimulation. Results CLL pts (n=17) had a significanty higher percentage of proliferating (Ki67+) CD3+ cells compared to HD (n=7) (median 3.7% in progressive vs 1.7% in indolent CLL vs 0.9% in HD, p=0.004 and p=0.04, respectively) (Fig.1). Progressive CLL pts had a significantly higher percentage Ki67+ CD4+ compared to indolent pts as well as HD (p=0.007 and p=0.001, respectively). Both indolent and progressive pts had higher percentage of Ki67+ CD8+ T cells compared to HD (p=0.01 and p=0.03, respectively). The percentage of CTLA-4+ CD4+ and CTLA-4+ CD8+ cells was low in CLL pts as well as in HD. However, the percentage of PD-1+ CD4+ T cells was significantly higher in progressive (n=32) as compared to indolent (n=35) CLL pts (median 40.3% vs 23.3%, p<0.0001) and HD (n=13) (median 21.5%, p<0.0001) (Fig.2) and correlated positively to the white blood cell counts (WBC) at the time of testing (r=0.29, p=0.03), while no difference was found with regard to the percentage of PD-1+ CD8+ T cells. No difference was observed between CLL pts and HD regarding the expression of PD-L1 on T cells. Both the percentage of CD69+ CD4+ and CD137+ CD4+ T cells were significantly higher in progressive as compared to indolent disease and correlated positively to WBC while no difference was found seen in CD8+ T cells. The percentage of CD103+ T cells was significantly lower in progressive compared to and HD within both the CD4+ (p=0.02) and the CD8+ subpopulations (p=0.02). After 72-hrs of PHA stimulation, PD-1 and CTLA-4 expression increased in CD4+ and CD8+ cells to a similar extent in CLL pts and HD, while PD-L1 increased in HD but not in progressive CLL pts (p=0.03 and p=0.007 for CD4+ and CD8+ cells, respectively). CD69 expression increased to a similar extent in CLL pts and HD, while CD137 expression increased more in T cells from progressive pts compared to HD (p=0.03 and 0.01 for the CD4+ and CD8+ cells, respectively). No increase in CD103 on CD8+ T-cells was observed in CLL pts compared to HD (p=0.04 and p=0.01 for the indolent and progressive pts, respectively). Conclusions Progressive CLL pts have more proliferating (Ki67+) T cells in both the CD4+ and CD8+ compartments compared to HD. CD4+ T-cells in progressive CLL pts display an activated phenotype (CD69+) and express the immune co-stimulatory molecule CD137 at a significantly higher level compared to indolent pts and HD. Nevertheless, the expression of the inhibitory immune checkpoint molecule PD-1 is so high that it is reasonable to assume that these cells are heavily impaired in their immune functions. The differences observed in the expression of immune checkpoints and activation markers between CLL pts in different phases of the disease suggest that major changes occur in the CD4+ T-cell compartment during disease progression. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Hansson: Jansse Cilag: Research Funding. Österborg:Janssen, Pharmacyclics, Gilead: Consultancy, Research Funding; Novartis: Research Funding.
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Martens, Jonas, Luc Janssens, Filip Staes, Bart Dingenen, and Daniel Daly. "Spectrum Analysis of Wireless Electromyography in Water and on Dry Land: A Single Case Example." Open Sports Sciences Journal 7, no. 1 (December 19, 2014): 198–202. http://dx.doi.org/10.2174/1875399x01407010198.
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Recent developments in wireless capture of muscle activity signals have improved the freedom of motion and the ease of use. Nevertheless, no study has examined the quality of wireless electromyographic technology during water activities. In this study the performance of a surface electromyography (SEMG) wireless system on dry land and in water was compared. Tibialis anterior muscle activity of 1 subject while contracting against a resistance of 84 Newton (N) was measured in 2 conditions: using a wireless (KINE) system with waterproof taping on the pool deck and submerged. Analysis of the raw signal showed acceptable ratios of 37 to 44 decibel (dB) between rest activity and the force activity at 84 N in both conditions. The total spectrum analysis and short term frequency analysis showed that no filtering occurred in either of the two conditions as frequencies were picked up in the entire spectrum. Spectrum analysis of rest activity or of the force buildup showed no spikes indicating any pickup of noise. The wireless system produced clean results and submersion and as a consequence recollection from the memory of the unit did not cause additional noise. Furthermore, the wireless system provided a satisfactory signal-to-rest activity ratio of approximately 40 dB and a range of 4 millivolts (mV). The KINE EMG units provided a valid means to analyze muscle activity during swimming while permitting unrestricted movement and ease of use.
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Barone, Martina, Francesca Ricci, Marco Romano, Dorian Forte, Giuseppe Auteri, Francesco Fabbri, Emanuela Ottaviani, et al. "The Infection-Driven Production/Secretion of Inflammatory Cytokines By Circulating Monocytes of Myelofibrosis Is Defective and Is Reactivated after In VivoJAK1/2 Inhibition." Blood 134, Supplement_1 (November 13, 2019): 1686. http://dx.doi.org/10.1182/blood-2019-127322.
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Introduction: Myelofibrosis (MF) is a chronic myeloproliferative neoplasm characterized by hyper-activation of the JAK-STAT pathway. More than half of the patients carries the JAK2V617F mutation. Cytokine overproduction, which is the hallmark of MF, is driven by multiple signaling pathways (NF-KB and MAPK) beyond JAK-STAT and is reduced but not abrogated by Ruxolitinib (RUX). RUX, which is the only JAK1/2 inhibitor approved for the treatment of splenomegaly and symptoms associated with MF, suppresses myeloproliferation (JAK2-driven) and release of pro-inflammatory cytokines (JAK1-driven). Microvesicles (MVs), which have a role in the inflammatory network and are critical players in the regulation of immunity through cytokine signaling, are released from a broad variety of cells with effects on communication among cells. Infections are one of the main causes of morbidity and mortality in MF. The increased infectious risk is thought to arise from dysfunction of key immune cells, including T, natural killer and dendritic cells, which further aggravates after JAK1/2 inhibition therapy. In this scenario, even though MF monocytes (Mo) are over-activated and show inflammatory features, their contribution still needs to be clarified. Aims: To study the role of circulating Mo in the inflammatory network of MF and to investigate whether and to what extent in vivoJAK1/2 inhibition may affects their in vitro cytokine producing ability. Methods: EDTA-anticoagulated peripheral blood was collected from 12 JAK2V617F mutatedMF patients before (Baseline) and after 6 months of RUX therapy and from 10 age/sex-matched healthy donors (HD). After 4 hours in vitro stimulation of mononuclear cells (PBMCs) with lipopolysaccharides (LPS) and in the presence of brefeldin A, the Interleukin (IL)-1β, -6, -10 and Tumor Necrosis Factor (TNF)-α producing Mo (CD14+ cells) were measured by intracellular staining and flow cytometry analysis. In parallel experiments, upon LPS stimulation, free and MVs-bound cytokines (IL-1β, IL-6, IL-10 and TNF-α) have been measured in the supernatants of immunomagnetically isolated HD/MF-Mo by flow cytometry. In addition, after isolation with ultracentrifugation from platelet poor plasma, titrating doses of circulating HD/MF MVs were co-cultured for 24 hours with immunomagnetically isolated HD-Mo and, upon LPS stimulation, inflammatory cytokines secretion was analysed in the supernatants by flow cytometry. Results: To characterize the cytokine producing ability of Mo we analyzed the IL1-β, TNF-α, IL-6 and IL-10 positive MF/HD Mo in response to LPS stimulation. At baseline, the percentages of MF-Mo producing pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) after 4 hours LPS stimulation was highly reduced as compared with the HD counterparts (Fig. 1). No IL-10-positive cells were detected with LPS stimulation (data not shown). To confirm the data, we analysed the free and MVs-bound cytokines in the culture supernatants upon LPS stimulation. At baseline, MF-Mo showed defective capacity to secrete free (Fig.2) and MVs-bound (Fig.3) IL-1β, IL-6, TNF-α and IL-10. Interestingly, the isolated circulating MF-MVs inhibited the LPS-driven inflammatory cytokines in vitro secretion of HD-Mo (Fig.4). Six months-RUX therapy reactivated the in vitro MF-Mo ability to produce intracellular inflammatory cytokines (Fig.1) and to secrete MVs-bound inflammatory cytokines in response to LPS stimulation (Fig.3). Conversely, the MF-Mo ability to secrete free cytokines in the supernatants in response to LPS stimulus remained lower than the HD counterparts (Fig.2). Conclusions: These data further refine the immune dysfunction of MF by demonstrating defective cytokine production/secretion of circulating Mo in response to infectious stimulus (LPS). This defect might be due, at least in part, to the inhibitory activity of circulating MF-MVs. Importantly, in vivoJAK1/2 inhibition ameliorates Mo cytokines production and promotes the MVs-based inflammatory cytokine signaling, suggesting that the increased infectious risk of MF patients undergoing RUX therapy is not due to defective inflammatory signals of circulating Mo. These findings contribute to better interpreting the off-target efficacy of JAK1/2 inhibition and to envisaging strategies aimed at facilitating the immune surveillance in MF. Disclosures Martinelli: BMS: Consultancy; Pfizer: Consultancy; ARIAD: Consultancy; Novartis: Consultancy; Roche: Consultancy. Cavo:janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Palandri:Novartis: Consultancy, Honoraria.
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Zhu, Yixiao, Xin Miao, Qi Wu, Longjie Yin, and Weisheng Hu. "Imbalanced Mach-Zehnder Modulator for Fading Suppression in Dispersion-Uncompensated Direct Detection System." Electronics 10, no. 22 (November 21, 2021): 2866. http://dx.doi.org/10.3390/electronics10222866.
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In this work, we systematically analyze the impact of three kinds of Mach-Zehnder modulator (MZM) imbalances, including bias deviation, amplitude mismatch, and differential time skew in intensity-modulation direct-detection (IM-DD) links. It is shown that, for power fading limited transmission, the imbalances can be utilized as advantages rather than impairments. Specifically, the bias deviation with single-arm driven mode and amplitude mismatch with differential driven mode can increase the available bandwidth by shifting the frequency of fading notches. Meanwhile, time skew provides another way to avoid fading by shaping the double sideband (DSB) signal into a vestigial sideband (VSB) with an asymmetrical transfer function. In the transmission experiment, 34 Gbaud Nyquist 6/8-ary pulse amplitude modulation (PAM-6/8) signals are used for investigation in a 20 km dispersion-uncompensated standard single-mode fiber (SSMF) link. With the help of a Volterra nonlinear equalizer, all three kinds of imbalances can achieve bit-error rates (BERs) below the 7% and 20% hard-decision forward error correction (HD-FEC) thresholds for PAM-6 and PAM-8 signals, respectively. The received power sensitivity is also compared at the back-to-back (BTB) case and after fiber transmission. Both numerical simulation and experimental demonstration confirm that the dispersion-induced power fading can be effectively suppressed with bias, amplitude, or skew imbalance, providing a feasible solution for transmission distance extension of C-band DD links.
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Baars, Holger, Patric Seifert, Ronny Engelmann, and Ulla Wandinger. "Target categorization of aerosol and clouds by continuous multiwavelength-polarization lidar measurements." Atmospheric Measurement Techniques 10, no. 9 (September 1, 2017): 3175–201. http://dx.doi.org/10.5194/amt-10-3175-2017.
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Abstract. Absolute calibrated signals at 532 and 1064 nm and the depolarization ratio from a multiwavelength lidar are used to categorize primary aerosol but also clouds in high temporal and spatial resolution. Automatically derived particle backscatter coefficient profiles in low temporal resolution (30 min) are applied to calibrate the lidar signals. From these calibrated lidar signals, new atmospheric parameters in temporally high resolution (quasi-particle-backscatter coefficients) are derived. By using thresholds obtained from multiyear, multisite EARLINET (European Aerosol Research Lidar Network) measurements, four aerosol classes (small; large, spherical; large, non-spherical; mixed, partly non-spherical) and several cloud classes (liquid, ice) are defined. Thus, particles are classified by their physical features (shape and size) instead of by source. The methodology is applied to 2 months of continuous observations (24 h a day, 7 days a week) with the multiwavelength-Raman-polarization lidar PollyXT during the High-Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE) in spring 2013. Cloudnet equipment was operated continuously directly next to the lidar and is used for comparison. By discussing three 24 h case studies, it is shown that the aerosol discrimination is very feasible and informative and gives a good complement to the Cloudnet target categorization. Performing the categorization for the 2-month data set of the entire HOPE campaign, almost 1 million pixel (5 min × 30 m) could be analysed with the newly developed tool. We find that the majority of the aerosol trapped in the planetary boundary layer (PBL) was composed of small particles as expected for a heavily populated and industrialized area. Large, spherical aerosol was observed mostly at the top of the PBL and close to the identified cloud bases, indicating the importance of hygroscopic growth of the particles at high relative humidity. Interestingly, it is found that on several days non-spherical particles were dispersed from the ground into the atmosphere.
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Deutsch, Yehuda E., Robert Wilkinson, Amanda Brahim, Stephanie Boisclair, Jose Sandoval-Sus, Annie Kuehnel, Terrence J. Bradley, et al. "Safety and Efficacy of Midostaurin in Combination with High-Dose Daunorubicin in 7+3 Induction for Acute Myeloid Leukemia with FLT3 Mutation." Blood 134, Supplement_1 (November 13, 2019): 3896. http://dx.doi.org/10.1182/blood-2019-129331.
Full textAbstract:
Introduction: Acute myeloid leukemia (AML) is a heterogeneous disease with varied outcomes dependent on patient cytogenetic and mutational status. Thirty percent of adults with newly diagnosed AML have a mutation in the fms-related tyrosine kinase 3 (FLT3) gene. Midostaurin is a small molecule inhibitor that acts on multiple receptor tyrosine kinases, including FLT3. The RATIFY trial showed improved overall survival (OS) and event-free survival in patients treated with daunorubicin and cytarabine (7+3) plus midostaurin (Stone et al, NEJM 2017). In this trial, a dose of daunorubicin 60 mg/m2 was administered. High dose (HD) 90 mg/m2 daunorubicin significantly improved the rate of complete remission and overall survival, including in patients with FLT3-ITD (Luskin et al, Blood 2016). HD daunorubicin has also been shown to be more effective than idarubicin in patients with FLT3-ITD AML (Lee et al, J Clin Oncol 2017). This data raises the question of whether the combination of midostaurin and HD daunorubicin would further improve outcomes of FLT3 mutated AML patients, while maintaining a tolerable safety profile. The objective of this study is to describe the safety and efficacy endpoints of FLT3 mutated AML patients treated with HD daunorubicin plus midostaurin as part of induction therapy. Methods: We retrospectively reviewed clinical and molecular data of patients at Memorial Healthcare System, Moffitt Cancer Center, and Sylvester Cancer Center with newly diagnosed FLT3 mutated AML treated from May 1st, 2017 to July 1st, 2019. Clinical data was abstracted in accordance with institutional review board approved protocol. All patients were induced with HD daunorubicin 90 mg/m2 on days 1-3, cytarabine 100 mg/m2 on days 1-7, and midostaurin 50 mg PO twice daily on days 8-21. Growth factor and antimicrobial support were used per institutional guidelines. Demographics were analyzed using descriptive statistics. OS was analyzed using Kaplan Meier method. Other efficacy outcomes were CR, CRi (assessed according to the European Leukemia Network Criteria for AML), proportion of patients needing re-induction, and proportion of patients who underwent hematopoietic stem cell transplant (HSCT). Safety outcomes were adverse events (AEs) and early (30- and 60-day) mortality. Results: Twenty-six patients were included in the final analysis. Patient characteristics are outlined in TABLE 1. All patients were FLT3 mutated, as confirmed with molecular studies. The FLT3 subtype was ITD (high) in 3 patients, ITD (low) in 16 patients, TKD in 5 patients, and both in 2 patients. Seventy-seven percent of patients achieved a CR/CRi after one induction cycle, and 96.2% attained CR after two induction cycles. Median time to ANC and platelet recovery was 28 and 26 days, respectively. One patient died during the first 60 days, due to Enterococcus sepsis. The most common non-hematological AEs were nausea (77%), diarrhea (62%), mucositis (58%), rash (54%), and increased ALT (54%). Cumulative incidence of relapse in the cohort was 28% (n=7). Four patients relapsed pre-transplant and achieved CR2 with additional therapy. All 7 of these patients had co-occurring mutations of various types. Of the 20 patients who were considered transplant eligible, 13 (65%) underwent HSCT and 4 (20%) are pending transplant. Of the 13 transplanted patients, 3 experienced relapse post-transplant. After a median follow up of 14.5 months, median OS has not been reached. Conclusion: In our multi-center experience, induction with HD daunorubicin, cytarabine, and midostaurin is clinically effective and seems to be well tolerated. Short term mortality was low and AEs were manageable, with no unexpected safety signals. Also, CR/CRi rates were higher than previously reported, suggesting that the combination of HD daunorubicin and midostaurin may improve the outcomes of patients with FLT3 mutated AML. Future analyses with larger patient samples and longer follow up are warranted to further evaluate long-term safety and efficacy for this regimen. Figure Disclosures Sandoval-Sus: Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Bradley:AbbVie: Other: Advisory Board. Talati:Agios: Honoraria; Celgene: Honoraria; Pfizer: Honoraria; Astellas: Honoraria, Speakers Bureau; Daiichi-Sankyo: Honoraria; Jazz Pharmaceuticals: Honoraria, Speakers Bureau. Watts:Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Sallman:Abbvie: Speakers Bureau; Novartis: Speakers Bureau; Jazz: Research Funding; Incyte: Speakers Bureau; Celyad: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding, Speakers Bureau. Sweet:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Celgene: Speakers Bureau; Jazz: Speakers Bureau; Incyte: Research Funding; Pfizer: Consultancy; Stemline: Consultancy; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees. Lancet:Daiichi Sankyo: Consultancy, Other: fees for non-CME/CE services ; Agios, Biopath, Biosight, Boehringer Inglheim, Celator, Celgene, Janssen, Jazz Pharmaceuticals, Karyopharm, Novartis: Consultancy; Pfizer: Consultancy, Research Funding.
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Guilluy, G., V. Andretta, F. Borsa, P. Giacobbe, A. Sozzetti, E. Covino, V. Bourrier, et al. "The GAPS programme at TNG." Astronomy & Astrophysics 639 (July 2020): A49. http://dx.doi.org/10.1051/0004-6361/202037644.
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Context. Exoplanets orbiting very close to their parent star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (He I) triplet at 1083.3 nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmospheres. Aims. We perform high-resolution transmission spectroscopy of the transiting hot Jupiter HD 189733 b with the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo, taking advantage of the simultaneous optical+near infrared spectral coverage to detect He I in the planet’s extended atmosphere and to gauge the impact of stellar magnetic activity on the planetary absorption signal. Methods. Observations were performed during five transit events of HD 189733 b. By comparison of the in-transit and out-of-transit GIANO-B observations, we computed high-resolution transmission spectra. We then used them to perform equivalent width measurements and carry out light-curves analyses in order to consistently gauge the excess in-transit absorption in correspondence with the He I triplet. Results. We spectrally resolve the He I triplet and detect an absorption signal during all five transits. The mean in-transit absorption depth amounts to 0.75 ± 0.03% (25σ) in the core of the strongest helium triplet component. We detect night-to-night variations in the He I absorption signal likely due to the transit events occurring in the presence of stellar surface inhomogeneities. We evaluate the impact of stellar-activity pseudo-signals on the true planetary absorption using a comparative analysis of the He I 1083.3 nm (in the near-infrared) and the Hα (in the visible) lines. Using a 3D atmospheric code, we interpret the time series of the He I absorption lines in the three nights not affected by stellar contamination, which exhibit a mean in-transit absorption depth of 0.77 ± 0.04% (19σ) in full agreement with the one derived from the full dataset. In agreement with previous results, our simulations suggest that the helium layers only fill part of the Roche lobe. Observations can be explained with a thermosphere heated to ~12 000 K, expanding up to ~1.2 planetary radii, and losing ~1 g s−1 of metastable helium. Conclusions. Our results reinforce the importance of simultaneous optical plus near infrared monitoring when performing high-resolution transmission spectroscopy of the extended and escaping atmospheres of hot planets in the presence of stellar activity.
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Rauw, Gregor, and Yaël Nazé. "Similar but different: the varied landscape of Onfp/Oef stars variability." Monthly Notices of the Royal Astronomical Society 500, no. 2 (October 27, 2020): 2096–111. http://dx.doi.org/10.1093/mnras/staa3310.
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ABSTRACT The Oef category gathers rapidly rotating and evolved O-stars displaying a centrally reversed He ii λ 4686 emission line. The origin of the variability of their photospheric and wind spectral lines is debated, with rotational modulation or pulsations as the main contenders. To shed new light on this question, we analysed high-quality and high-cadence Transiting Exoplanet Survey Satellite photometric time series for five Oef stars. We also collected a new time series of spectra for one target (λ Cep) which had been the subject of specific debates in the last years. These observations reveal the variety of Oef behaviours. While space-based photometric data reveal substantial red noise components in all targets, only ζ Pup seems to display a long-lived periodicity. In our sample, stars exhibit a dominant signal at low frequencies but it appears relatively short-lived. This is reminiscent of rotational modulations by transient photospheric spots, though this scenario is challenged by the case of HD 14 442, whose 1.230 d−1 signal significantly exceeds the critical rotational frequency. In parallel, no evidence of persistent p mode non-radial pulsations is found in either photometry or spectroscopy of the stars, only temporary excitation of g mode pulsations could offer an alternative explanation for the dominant signals. Finally, the revised luminosities of the stars using GAIA-DR2 show that they are not all supergiants as ζ Pup. The question then arises whether the Oef peculiarity denotes a homogeneous class of objects after all.
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Meech, Annabella, Suzanne Aigrain, Matteo Brogi, and Jayne L. Birkby. "Applications of a Gaussian process framework for modelling of high-resolution exoplanet spectra." Monthly Notices of the Royal Astronomical Society 512, no. 2 (March 12, 2022): 2604–17. http://dx.doi.org/10.1093/mnras/stac662.
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ABSTRACT Observations of exoplanet atmospheres in high resolution have the potential to resolve individual planetary absorption lines, despite the issues associated with ground-based observations. The removal of contaminating stellar and telluric absorption features is one of the most sensitive steps required to reveal the planetary spectrum and, while many different detrending methods exist, it remains difficult to directly compare the performance and efficacy of these methods. Additionally, though the standard cross-correlation method enables robust detection of specific atmospheric species, it only probes for features that are expected a priori. Here, we present a novel methodology using Gaussian process (GP) regression to directly model the components of high-resolution spectra, which partially addresses these issues. We use two archival CRyogenic Infra-Red Echelle Spectrograph (CRIRES)/Very Large Telescope (VLT) data sets as test cases, observations of the hot Jupiters HD 189733 b and 51 Pegasi b, recovering injected signals with average line contrast ratios of ∼4.37 × 10−3 and ∼1.39 × 10−3, and planet radial velocities ΔKp = 1.45 ± 1.53 $\mathrm{km\, s^{-1}}$ and ΔKp = 0.12 ± 0.12 $\mathrm{km\, s^{-1}}$ from the injection velocities, respectively. In addition, we demonstrate an application of the GP method to assess the impact of the detrending process on the planetary spectrum, by implementing injection-recovery tests. We show that standard detrending methods used in the literature negatively affect the amplitudes of absorption features in particular, which has the potential to render retrieval analyses inaccurate. Finally, we discuss possible limiting factors for the non-detections using this method, likely to be remedied by higher signal-to-noise data.
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Zhang, Fan, and Feng Wang. "Exercise and Rehabilitation of Chronically Ill Patients Assisted by Small Digital Bio-Pulse Sensors." Mathematical Problems in Engineering 2022 (April 15, 2022): 1–11. http://dx.doi.org/10.1155/2022/3463274.
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With the continuous increase of the ageing population, the number of patients with chronic diseases has increased dramatically. The limited medical resources and the strong demand for high-quality medical services are in stark contradiction. Active rehabilitation training is one of the most effective rehabilitation methods, but it is difficult to achieve through traditional medical equipment. In this paper, aiming at effective clinical rehabilitation, an in-depth study was carried out on the exercise intention recognition experiment of patients, hoping to provide an effective rehabilitation treatment method for the recovery of patients with lower extremity motor function injury. This paper introduces the detection principle of the photoelectric pulse sensor and the design scheme that is used in physical education. In the experiment, through the hardware connection, programming, and the development of the host computer software, the pulse signal of the human body can be presented stably on the computer. The monitoring of the pulse of the students can help the physical education teacher to understand the situation of the students and prevent accidents. In addition, we believe that the acquisition of students’ pulse signals in physical education to build a database is of great significance for research and tracking of students’ health status and the research results will certainly promote the development of pulse diagnosis. In order to make the lower extremity exoskeleton rehabilitation system that can be applied in clinical rehabilitation, according to the Brunnstrom staging of patients with central nervous system injury, the needs of patients in different stages in the rehabilitation process were analysed and active and passive lower extremity rehabilitation strategies were formulated. Aiming at the problem of real-time and accurate identification of human motion intention, and to alleviate the mechanism motion delay caused by the delay of mechanical and control systems in the human-machine integrated system, a differential sEMG real-time feature extraction algorithm is proposed. The results show that the sensor and monitoring system have excellent stability, and the auxiliary system can accurately reflect the changing trend of the human biological pulse, achieve the expected effect, and effectively assist in the monitoring of exercise data for patients with chronic diseases. After treatment, the joint range of motion and muscle strength basically returned to normal levels, and the patient was able to walk independently. Compared with traditional treatment methods, the recovery time is shorter, the recovery of muscle strength is more effective, and the medical staff is more relaxed.
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Manfredi, Francesco, Maddalena Noviello, Eliana Ruggiero, Tommaso Perini, Giacomo Oliveira, Filippo Cortesi, Pantaleo De Simone, et al. "Exhausted Central Memory and Memory Stem T Cells Specific for Leukemia Infiltrate the Bone Marrow of AML Patients Relapsing after Allogeneic HSCT." Blood 132, Supplement 1 (November 29, 2018): 2028. http://dx.doi.org/10.1182/blood-2018-99-118104.
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Abstract Background. Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) is the only cure for high-risk acute myeloid leukemia (AML); nonetheless, relapse remains the major cause of death after such therapeutic option. Patients and Methods . We investigated the expression of Inhibitory Receptors (IR; i.e. PD-1, CTLA-4, TIM-3, LAG-3 and KLRG1) on different T-cell subsets infiltrating the bone marrow (BM) of 8 healthy donors (HD) and 32 allogeneic HSCT recipients diagnosed with Acute Myeloid Leukemia, collected at relapse (median 251 days) or at complete remission (CR) 1 year after HSCT. Inclusion criteria were: a diagnosis of acute myeloid leukemia or myelodysplastic syndrome, a relapse-free survival of at least 4 months after allogenein HSCT, absence of active GvHD, CMV infections or other complications at the time of sampling. Samples were analysed by multi-parametric flow cytometry for the expression of inhibitory receptors on T-cell subsets and the results were validated with BH-SNE, an unbiased dimensionality reduction algorithm. We exploited HLA-mimicking fluorescent molecules loaded with a specific epitope to screen anti-tumour and anti-viral T cells whereas the T-cell receptor repertoire was assessed by TRAC and TRBC RNA sequencing and the relative frequency of each T-cell receptor calculated. To evaluate T-cell function and specificity, CD107a expression, cytokine profiles and killing of autologous blasts were quantified. Results. After Haploidentical-HSCT PD-1, CTLA-4, 2B4 and Tim-3 were expressed at higher percentage when compared to HD, independently from the clinical outcome. In contrast, after HLA-matched HSCT, patients who relapsed displayed a higher frequency of BM-infiltrating T cells expressing PD-1, CTLA-4 and Tim-3 than CR pts (p<0.05) or HD samples (p<0.01). These data were validated by BH-SNE, who retrieved 32 clusters associated with relapse and composed of T cells co-expressing multiple IRs at high fluorescence, indicating a dominant inhibitory T-cell profile in the BM of relapsing patients. To further corroborate the biological relevance of immune checkpoints in the context of post-transplant relapse we typed AML cells, detecting high levels of the IRs ligands PD-L1, CD48, Galectin-9 and CD80/86 on blasts. To gain insights on the inhibited T-cell subpopulation identified in the BM of relapsing patients, we separately profiled the different T-cell memory subsets: in both HD and CR patients the IR expression was confined to effector memory and effectors whereas at relapse PD-1, 2B4, KLRG1 and Tim-3 were also expressed in BM-infiltrating central memory (TCM) and memory stem T cells (TSCM, p<0.01), thus indicating a pervasive and profound immune suppression that specifically involved the memory T-cell compartment. In accordance to this exhausted phenotype, we observed that BM CD8 T cells at relapse displayed lower degranulation ability and IL-2 production compared to CR (p<0.05). Notably, this functional impairment could be reversed by in vitro culture with high doses of IL-2. Interestingly, the TCR repertoire of BM-infiltrating T cells at relapse displayed a restricted clonality, suggesting that immune inhibitory signals are active on discrete and specific T-cell clones. To gain further insights on such clones, we assessed the IR expression profile on CD8 T cells specific for viral (CMV) and tumor-associated antigens (including peptides from WT1, EZH2 and PRAME). We observed a higher IR expression and co-expression on tumor-specific T cells when compared to viral-specific CD8 cells, particularly in case of patients who experienced post-transplant relapse. In accordance, IRpos sorted T cells harvested from relapsing patients showed a restricted TCR repertoire and, when challenged with autologous leukemic blasts, proved enriched in leukemic specificities as shown by higher expression of the activation marker HLA-DR (p<0.05), higher granzyme A and B production (p<0.001) and higher blast lysis in cytotoxicity assays (p<0.05) when compared to IRneg T cells. Conclusion. These results highlight a wide, yet reversible, immunological dysfunction likely mediated by AML blasts in the BM of patients relapsing after allogeneic HSCT, that is particularly evident on memory T cells specific for tumor antigens. This suggest and open new therapeutic opportunities for AML. Figure. Figure. Disclosures Bondanza: Novartis: Employment. Vago:GENDX: Research Funding; Moderna TX: Research Funding. Bonini:Intellia Therapeutics: Research Funding.
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Di Girolamo, Paolo, Marco Cacciani, Donato Summa, Andrea Scoccione, Benedetto De Rosa, Andreas Behrendt, and Volker Wulfmeyer. "Characterisation of boundary layer turbulent processes by the Raman lidar BASIL in the frame of HD(CP)<sup>2</sup> Observational Prototype Experiment." Atmospheric Chemistry and Physics 17, no. 1 (January 17, 2017): 745–67. http://dx.doi.org/10.5194/acp-17-745-2017.
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Abstract. Measurements carried out by the University of Basilicata Raman lidar system (BASIL) are reported to demonstrate the capability of this instrument to characterise turbulent processes within the convective boundary layer (CBL). In order to resolve the vertical profiles of turbulent variables, high-resolution water vapour and temperature measurements, with a temporal resolution of 10 s and vertical resolutions of 90 and 30 m, respectively, are considered. Measurements of higher-order moments of the turbulent fluctuations of water vapour mixing ratio and temperature are obtained based on the application of autocovariance analyses to the water vapour mixing ratio and temperature time series. The algorithms are applied to a case study (11:30–13:30 UTC, 20 April 2013) from the High Definition Clouds and Precipitation for Climate Prediction (HD(CP)2) Observational Prototype Experiment (HOPE), held in western Germany in the spring 2013. A new correction scheme for the removal of the elastic signal crosstalk into the low quantum number rotational Raman signal is applied. The noise errors are small enough to derive up to fourth-order moments for both water vapour mixing ratio and temperature fluctuations.To the best of our knowledge, BASIL is the first Raman lidar with a demonstrated capability to simultaneously retrieve daytime profiles of water vapour turbulent fluctuations up to the fourth order throughout the atmospheric CBL. This is combined with the capability of measuring daytime profiles of temperature fluctuations up to the fourth order. These measurements, in combination with measurements from other lidar and in situ systems, are important for verifying and possibly improving turbulence and convection parameterisation in weather and climate models at different scales down to the grey zone (grid increment ∼ 1 km; Wulfmeyer et al., 2016).For the considered case study, which represents a well-mixed and quasi-stationary CBL, the mean boundary layer height is found to be 1290 ± 75 m above ground level (a.g.l.). Values of the integral scale for water vapour and temperature fluctuations at the top of the CBL are in the range of 70–125 and 75–225 s, respectively; these values are much larger than the temporal resolution of the measurements (10 s), which testifies that the temporal resolution considered for the measurements is sufficiently high to resolve turbulent processes down to the inertial subrange and, consequently, to resolve the major part of the turbulent fluctuations. Peak values of all moments are found in the interfacial layer in the proximity of the top of the CBL. Specifically, water vapour and temperature second-order moments (variance) have maximum values of 0.29 g2 kg−2 and 0.26 K2; water vapour and temperature third-order moments have peak values of 0.156 g3 kg−3 and −0.067 K3, while water vapour and temperature fourth-order moments have maximum values of 0.28 g4 kg−4 and 0.24 K4. Water vapour and temperature kurtosis have values of ∼ 3 in the upper portion of the CBL, which indicate normally distributed humidity and temperature fluctuations. Reported values of the higher-order moments are in good agreement with previous measurements at different locations, thus providing confidence in the possibility of using these measurements for turbulence parameterisation in weather and climate models.In the determination of the temperature profiles, particular care was dedicated to minimise potential effects associated with elastic signal crosstalk on the rotational Raman signals. For this purpose, a specific algorithm was defined and tested to identify and remove the elastic signal crosstalk and to assess the residual systematic uncertainty affecting temperature measurements after correction. The application of this approach confirms that, for the present Raman lidar system, the crosstalk factor remains constant with time; consequently an appropriate assessment of its constant value allows for a complete removal of the leaking elastic signal from the rotational Raman lidar signals at any time (with a residual error on temperature measurements after correction not exceeding 0.18 K).
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Olive, Daniel, Kieu Suong Le, Mikael Roussel, Florence Broussais, Imane Azzaoui, Delphine Rossille, Reda Bouabdallah, et al. "Diffuse Large B Cell Lymphoma (DLBCL) infiltrating T Cells Display an Activated and Exhausted Status and Are Inhibited By Ligands of Cosignaling Receptors Including PD-L1, PD-L2 and CD80 Expressed By Most DLBCL in Situ." Blood 124, no. 21 (December 6, 2014): 1665. http://dx.doi.org/10.1182/blood.v124.21.1665.1665.
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Abstract The regulation of immune response through cosignaling receptors is the major mechanism that prevent normal responses against peripheral tissues but that is used by tumor to hijack the autologous immune responses. This therapy are currently among the most promising adjuvant therapy in cancers including lymphomas. In addition sPDL1 is an important marker of patient's prognosis (Rossille et al., Leukemia 2014) Our objective was the study of the expression of ligands by activating receptors on diffuse large B cell lymphoma (DLBCL) in comparison to Follicular Lymphoma (FL), Hodgkin Lymphoma (HL) and hyperplasia and to investigate the status of the infiltrating immune system as well as the function of the sorted autologous interaction of T cells against autologous DLBCL Methods: We have dissociated fresh tumor B cell samples ( FL= 13, HD= 15, DLBCL = 15) and analysed the immune microenvironment and DLBCL by flow cytometry using mAbs recognizing cosignaling molecules of 15 samples. In a second step we have sorted the T cells and autologous DLBCL and performed cocultures with the coincubation with antagonist PD1 (PD1.3.1) PDL1 (PDL1.3.1) PDL2 (PDL2.1), Tim3 and CD80 mAbs. T cell stimulation was performed for 5 days. We have previously described the proprietary antagonist PD1, PDL1, PDL2 and CD80 used (Serriari et al., J. Immunol., 2010; Ghiotto et al. , Int.Immunol., 2010) Results: The immune cells including T cells present within the DLBCL microenvironment are characterized by a highly activated /exhausted status as evidenced by the expression of PD-1, PDL1, PDL2, CD80 and Tim3 Figure 1) . Importantly most of these receptors are involved in negative signals provided their ligand is expressed on their cognate target cell. PDL1, PDL2 and CD80 are both present on DLBCL with some degree of heterogeneity among tumors and surprisingly PD1. Autologous T cell and lymphoma cells were sorted and autologous responses such as proliferation and cytokine production were analysed after in vitro culture without or with antagonist mAbs directed against cosignaling receptors. We could evidence for the first time to our knowledge that blockade of PD1 and CD80 pathways induced /restored the autologous response of infiltrating T cells. Conclusions: These data demonstrate that a subgroup of DLBCL patients might benefit from treatment with checkpoint blockade mAbs. A major objective is to understand the molecular basis of DLBCL heterogeneity that currently investigated. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.
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Yamada, Kyohei, Hiroaki Miyoshi, Mai Takeuchi, Naoko Asano, Joji Shimono, Fumiko Arakawa, Kazutaka Nakashima, Kensaku Sato, Masao Seto, and Koichi Ohshima. "In Situ Hybridization of HBZ and Tax in FFPE Samples from ATLL Patients and Its Association with Clinicopathological Characteristics." Blood 132, Supplement 1 (November 29, 2018): 1643. http://dx.doi.org/10.1182/blood-2018-99-112082.
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Abstract Introduction Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). Many studies on HTLV-1-related mRNA including HTLV-1 bZIP factor (HBZ) and Tax have been performed, mainly using cell lines, patient-derived cells, and mice. However, there are scant data concerning HTLV-1-related mRNA in formalin-fixed, paraffin-embedded (FFPE) tissue samples. We detected HBZ and Tax mRNA on FFPE tissue samples using in situ hybridization (ISH), and investigated the association with clinicopathological characteristics. Materials and methods Eighty-seven biopsy samples from newly diagnosed ATLL patients were examined. The same samples were used in a previous study (Miyoshi et al. Blood, 2016). Use of patient materials and clinical information was approved by the Ethical Committee of Kurume University, in accordance with the Declaration of Helsinki. ISH was performed on FFPE tissue samples using RNAscope 2.5 HD Reagent Kit-BROWN (Advanced Cell Diagnostics, Hayward, CA). HBZ-and Tax-specific probes were used. MT-4 (HTLV-1 immortalized cell line) and Jurkat (T-cell acute lymphoblastic leukemia cell line) were used as positive and negative controls, respectively. Dot-like signals were counted at high magnification (40 diameters) on 10 randomly selected fields and the number of signals per 1,000 ATLL cells were calculated. The results were reviewed by two experienced hematopathologists. High expression was indicated when more than the median value of HBZ or Tax signals was stained. The antibodies for immunohistochemistry targeted CD4, CD30, Ki-67(MIB-1), CCR4, FoxP3, GATA3, IRF4, HLA class I, β2-microglobulin (β2M), PD-1, and PD-L1. Clinicopathological characteristics of ATLL patients were compared by Fisher's exact test (2-sided), Mann-Whitney's U test, and Spearman's rank correlation analysis. Overall survival was estimated by the Kaplan-Meier method and compared by the Log-rank test. P< .05 was considered statistically significant. EZR ver. 1.32 was used for all statistical analyses. Results In the histogram and scatter plot of HBZ-ISH and Tax-ISH, the median values of HBZ signals and Tax signals were 806/1000 ATLL cells (range 0.4 - 4013.1) and 5.0/1000 ATLL cells (range 0.1 - 891.2), respectively (Figure 1). Representative samples of HBZ-ISH and Tax-ISH are presented in Figure 2A and 2B, respectively. Notably, the high-expression group of HBZ displayed significant reductions in skin lesions (P = .025), Ann Arbor stage (P = .021), and peripheral blood involvement (P = .028). The high-expression group of Tax displayed significant increases in lactate dehydrogenase activity (P = .0020), splenomegaly (P = .0070), CD 30 (P = .015), and PD-1 in tumor-infiltrating lymphocytes (PD-1_TIL; P <.0010). Weak but significant positive correlation was observed between HBZ and IRF4 (ρ = .33; P = .029), between HBZ and PD-L1 (ρ = -. 28; P = .010), between Tax and CD4 (ρ = .41; P = .0074), between Tax and CD30 (ρ = .26; P = .016), between Tax and GATA 3 (ρ = .26; P = .014), between Tax and PD-1 in ATLL cells (ρ = .25; P = .0074), between Tax and PD-L1 in ATLL cells (ρ =. 32; P = .0026), and between Tax and PD-1_TIL (ρ = .37; p = .0026) (Figure 3). There was almost no correlation between HBZ and Tax (ρ = .052; P = .63). There were no significant differences between HBZ or Tax and OS (Log-rank P = .21 and .95, respectively). Conclusion The RNA scope assay is useful for detecting low expressing mRNA in FFPE tissue samples. Our data suggest that ISH of HBZ and Tax can detect differences in clinicopathological characteristics of ATLL patients. In clinical and cell samples, HBZ and Tax might be involved in the pathogenesis of ATLL. Disclosures No relevant conflicts of interest to declare. Disclosures Asano: Takeda: Honoraria; Chugai Pharma: Honoraria; Celgene: Honoraria.